diff --git a/src/ASPHERE/compute_temp_asphere.h b/src/ASPHERE/compute_temp_asphere.h
index 0151ff9961..4688a5612d 100755
--- a/src/ASPHERE/compute_temp_asphere.h
+++ b/src/ASPHERE/compute_temp_asphere.h
@@ -86,6 +86,7 @@ compute.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/ASPHERE/pair_line_lj.h b/src/ASPHERE/pair_line_lj.h
index 4867422baf..8722352e59 100644
--- a/src/ASPHERE/pair_line_lj.h
+++ b/src/ASPHERE/pair_line_lj.h
@@ -81,6 +81,7 @@ Self-explanatory.
 
 E: All pair coeffs are not set
 
-UNDOCUMENTED
+All pair coefficients must be set in the data file or by the
+pair_coeff command before running a simulation.
 
 */
diff --git a/src/BODY/body_nparticle.h b/src/BODY/body_nparticle.h
index c81aa288d9..df968aac09 100644
--- a/src/BODY/body_nparticle.h
+++ b/src/BODY/body_nparticle.h
@@ -75,9 +75,4 @@ E: Insufficient Jacobi rotations for body nparticle
 
 Eigensolve for rigid body was not sufficiently accurate.
 
-U: Invalid format in Bodies section of data file
-
-The specified number of integer or floating point values does not
-appear.
-
 */
diff --git a/src/COMPRESS/dump_atom_gz.h b/src/COMPRESS/dump_atom_gz.h
index 57897b0c8c..bd0ed792f8 100644
--- a/src/COMPRESS/dump_atom_gz.h
+++ b/src/COMPRESS/dump_atom_gz.h
@@ -52,6 +52,6 @@ The dump atom/gz output file name must have a .gz suffix.
 
 E: Cannot open dump file
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/COMPRESS/dump_cfg_gz.h b/src/COMPRESS/dump_cfg_gz.h
index 7da426e6c8..aefde431cf 100644
--- a/src/COMPRESS/dump_cfg_gz.h
+++ b/src/COMPRESS/dump_cfg_gz.h
@@ -52,6 +52,6 @@ The dump cfg/gz output file name must have a .gz suffix.
 
 E: Cannot open dump file
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/COMPRESS/dump_custom_gz.h b/src/COMPRESS/dump_custom_gz.h
index fab5826d46..3a75673ab5 100644
--- a/src/COMPRESS/dump_custom_gz.h
+++ b/src/COMPRESS/dump_custom_gz.h
@@ -52,6 +52,6 @@ The dump custom/gz output file name must have a .gz suffix.
 
 E: Cannot open dump file
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/COMPRESS/dump_xyz_gz.h b/src/COMPRESS/dump_xyz_gz.h
index b8aff215cf..45d5456ddb 100644
--- a/src/COMPRESS/dump_xyz_gz.h
+++ b/src/COMPRESS/dump_xyz_gz.h
@@ -52,6 +52,6 @@ The dump xyz/gz output file name must have a .gz suffix.
 
 E: Cannot open dump file
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/CORESHELL/compute_temp_cs.h b/src/CORESHELL/compute_temp_cs.h
index d54b2d0ee7..5a1d1434c3 100644
--- a/src/CORESHELL/compute_temp_cs.h
+++ b/src/CORESHELL/compute_temp_cs.h
@@ -103,6 +103,7 @@ Could not find or more atoms in the bond pairs.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/GPU/pair_eam_alloy_gpu.h b/src/GPU/pair_eam_alloy_gpu.h
index 1c893363dd..eb1ff404b0 100644
--- a/src/GPU/pair_eam_alloy_gpu.h
+++ b/src/GPU/pair_eam_alloy_gpu.h
@@ -58,11 +58,12 @@ public:
 
 E: Insufficient memory on accelerator
 
-UNDOCUMENTED
+There is insufficient memory on one of the devices specified for the gpu
+package
 
 E: Cannot use newton pair with eam/alloy/gpu pair style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Incorrect args for pair coefficients
 
diff --git a/src/GPU/pair_eam_fs_gpu.h b/src/GPU/pair_eam_fs_gpu.h
index 0d038ea91c..03c6d189b2 100644
--- a/src/GPU/pair_eam_fs_gpu.h
+++ b/src/GPU/pair_eam_fs_gpu.h
@@ -58,11 +58,12 @@ public:
 
 E: Insufficient memory on accelerator
 
-UNDOCUMENTED
+There is insufficient memory on one of the devices specified for the gpu
+package
 
 E: Cannot use newton pair with eam/fs/gpu pair style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Incorrect args for pair coefficients
 
diff --git a/src/GPU/pair_lj_cubic_gpu.h b/src/GPU/pair_lj_cubic_gpu.h
index 99f85f0958..1591eb8b9e 100644
--- a/src/GPU/pair_lj_cubic_gpu.h
+++ b/src/GPU/pair_lj_cubic_gpu.h
@@ -53,10 +53,6 @@ package
 
 E: Cannot use newton pair with lj/cubic/gpu pair style
 
-UNDOCUMENTED
-
-U: Cannot use newton pair with lj/cut/gpu pair style
-
 Self-explanatory.
 
 */
diff --git a/src/GPU/pair_tersoff_gpu.h b/src/GPU/pair_tersoff_gpu.h
index b7d384e043..4fa358a6b1 100644
--- a/src/GPU/pair_tersoff_gpu.h
+++ b/src/GPU/pair_tersoff_gpu.h
@@ -56,7 +56,7 @@ package
 
 E: Pair style tersoff/gpu requires atom IDs
 
-UNDOCUMENTED
+This is a requirement to use the tersoff/gpu potential.
 
 E: Pair style tersoff/gpu requires newton pair off
 
diff --git a/src/GPU/pair_zbl_gpu.h b/src/GPU/pair_zbl_gpu.h
index 3255e6e043..0939dafaaa 100644
--- a/src/GPU/pair_zbl_gpu.h
+++ b/src/GPU/pair_zbl_gpu.h
@@ -53,10 +53,6 @@ package
 
 E: Cannot use newton pair with zbl/gpu pair style
 
-UNDOCUMENTED
-
-U: Cannot use newton pair with gauss/gpu pair style
-
-Self-explanatory.
+Self-explantory.
 
 */
diff --git a/src/GRANULAR/pair_gran_hooke_history.cpp b/src/GRANULAR/pair_gran_hooke_history.cpp
index 208d300083..05fee0c8d6 100644
--- a/src/GRANULAR/pair_gran_hooke_history.cpp
+++ b/src/GRANULAR/pair_gran_hooke_history.cpp
@@ -394,7 +394,7 @@ void PairGranHookeHistory::init_style()
   // error and warning checks
 
   if (!atom->radius_flag || !atom->rmass_flag)
-    error->all(FLERR,"Pair granular requires atom atrributes radius, rmass");
+    error->all(FLERR,"Pair granular requires atom atributes radius, rmass");
   if (comm->ghost_velocity == 0)
     error->all(FLERR,"Pair granular requires ghost atoms store velocity");
 
diff --git a/src/GRANULAR/pair_gran_hooke_history.h b/src/GRANULAR/pair_gran_hooke_history.h
index 493dc39e07..1e58ad48e0 100644
--- a/src/GRANULAR/pair_gran_hooke_history.h
+++ b/src/GRANULAR/pair_gran_hooke_history.h
@@ -85,7 +85,7 @@ Self-explanatory.  Check the input script or data file.
 
 E: Pair granular requires atom atrributes radius, rmass
 
-UNDOCUMENTED
+The atom style defined does not have these attributes.
 
 E: Pair granular requires ghost atoms store velocity
 
@@ -98,10 +98,7 @@ granular styles with history.
 
 E: Could not find pair fix ID
 
-UNDOCUMENTED
-
-U: Pair granular requires atom style sphere
-
-Self-explanatory.
+A fix is created internally by the pair style to store shear
+history information.  You cannot delete it.
 
 */
diff --git a/src/KOKKOS/atom_kokkos.h b/src/KOKKOS/atom_kokkos.h
index 53f0b91f5f..9bcd07aa4f 100644
--- a/src/KOKKOS/atom_kokkos.h
+++ b/src/KOKKOS/atom_kokkos.h
@@ -112,6 +112,6 @@ class SortFunctor {
 
 E: KOKKOS package requires a kokkos enabled atom_style
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/atom_vec_full_kokkos.cpp b/src/KOKKOS/atom_vec_full_kokkos.cpp
index d41a88bd88..10043d5dd0 100644
--- a/src/KOKKOS/atom_vec_full_kokkos.cpp
+++ b/src/KOKKOS/atom_vec_full_kokkos.cpp
@@ -764,11 +764,8 @@ struct AtomVecFullKokkos_PackBorder {
   union ubuf {
     double d;
     int64_t i;
-    KOKKOS_INLINE_FUNCTION
     ubuf(double arg) : d(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int64_t arg) : i(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int arg) : i(arg) {}
   };
 
@@ -1033,11 +1030,8 @@ struct AtomVecFullKokkos_UnpackBorder {
   union ubuf {
     double d;
     int64_t i;
-    KOKKOS_INLINE_FUNCTION
     ubuf(double arg) : d(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int64_t arg) : i(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int arg) : i(arg) {}
   };
 
@@ -1183,11 +1177,8 @@ struct AtomVecFullKokkos_PackExchangeFunctor {
   union ubuf {
     double d;
     int64_t i;
-    KOKKOS_INLINE_FUNCTION
     ubuf(double arg) : d(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int64_t arg) : i(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int arg) : i(arg) {}
   };
 
@@ -1536,11 +1527,8 @@ struct AtomVecFullKokkos_UnpackExchangeFunctor {
   union ubuf {
     double d;
     int64_t i;
-    KOKKOS_INLINE_FUNCTION
     ubuf(double arg) : d(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int64_t arg) : i(arg) {}
-    KOKKOS_INLINE_FUNCTION
     ubuf(int arg) : i(arg) {}
   };
 
diff --git a/src/KOKKOS/compute_temp_kokkos.h b/src/KOKKOS/compute_temp_kokkos.h
index e33eb2bca2..2bb0f9cbb2 100755
--- a/src/KOKKOS/compute_temp_kokkos.h
+++ b/src/KOKKOS/compute_temp_kokkos.h
@@ -100,12 +100,7 @@ class ComputeTempKokkos : public ComputeTemp {
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
-
-U: Illegal ... command
-
-Self-explanatory.  Check the input script syntax and compare to the
-documentation for the command.  You can use -echo screen as a
-command-line option when running LAMMPS to see the offending line.
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/KOKKOS/dihedral_opls_kokkos.h b/src/KOKKOS/dihedral_opls_kokkos.h
index 5bf2552d9b..183c39ea37 100755
--- a/src/KOKKOS/dihedral_opls_kokkos.h
+++ b/src/KOKKOS/dihedral_opls_kokkos.h
@@ -13,9 +13,9 @@
 
 #ifdef DIHEDRAL_CLASS
 
-DihedralStyle(opls/kk,DihedralOPLSKokkos<LMPDeviceType>)
-DihedralStyle(opls/kk/device,DihedralOPLSKokkos<LMPDeviceType>)
-DihedralStyle(opls/kk/host,DihedralOPLSKokkos<LMPHostType>)
+DihedralStyle(charmm/kk,DihedralOPLSKokkos<LMPDeviceType>)
+DihedralStyle(charmm/kk/device,DihedralOPLSKokkos<LMPDeviceType>)
+DihedralStyle(charmm/kk/host,DihedralOPLSKokkos<LMPHostType>)
 
 #else
 
diff --git a/src/KOKKOS/domain_kokkos.h b/src/KOKKOS/domain_kokkos.h
index 96dd75fdec..50429008dc 100644
--- a/src/KOKKOS/domain_kokkos.h
+++ b/src/KOKKOS/domain_kokkos.h
@@ -65,6 +65,6 @@ class DomainKokkos : public Domain {
 
 E: Illegal simulation box
 
-UNDOCUMENTED
+The lower bound of the simulation box is greater than the upper bound.
 
 */
diff --git a/src/KOKKOS/fix_deform_kokkos.h b/src/KOKKOS/fix_deform_kokkos.h
index f0330046b5..8fa12a2e37 100755
--- a/src/KOKKOS/fix_deform_kokkos.h
+++ b/src/KOKKOS/fix_deform_kokkos.h
@@ -46,63 +46,6 @@ class FixDeformKokkos : public FixDeform {
 
 E: Cannot (yet) use rigid bodies with fix deform and Kokkos
 
-UNDOCUMENTED
-
-U: Illegal ... command
-
-Self-explanatory.  Check the input script syntax and compare to the
-documentation for the command.  You can use -echo screen as a
-command-line option when running LAMMPS to see the offending line.
-
-U: Fix deform tilt factors require triclinic box
-
-Cannot deform the tilt factors of a simulation box unless it
-is a triclinic (non-orthogonal) box.
-
-U: Cannot use fix deform on a shrink-wrapped boundary
-
-The x, y, z options cannot be applied to shrink-wrapped
-dimensions.
-
-U: Cannot use fix deform tilt on a shrink-wrapped 2nd dim
-
-This is because the shrink-wrapping will change the value
-of the strain implied by the tilt factor.
-
-U: Fix deform volume setting is invalid
-
-Cannot use volume style unless other dimensions are being controlled.
-
-U: More than one fix deform
-
-Only one fix deform can be defined at a time.
-
-U: Variable name for fix deform does not exist
-
-Self-explantory.
-
-U: Variable for fix deform is invalid style
-
-The variable must be an equal-style variable.
-
-U: Final box dimension due to fix deform is < 0.0
-
 Self-explanatory.
 
-U: Cannot use fix deform trate on a box with zero tilt
-
-The trate style alters the current strain.
-
-U: Fix deform cannot use yz variable with xy
-
-The yz setting cannot be a variable if xy deformation is also
-specified.  This is because LAMMPS cannot determine if the yz setting
-will induce a box flip which would be invalid if xy is also changing.
-
-U: Fix deform is changing yz too much with xy
-
-When both yz and xy are changing, it induces changes in xz if the
-box must flip from one tilt extreme to another.  Thus it is not
-allowed for yz to grow so much that a flip is induced.
-
 */
diff --git a/src/KOKKOS/fix_nh_kokkos.h b/src/KOKKOS/fix_nh_kokkos.h
index 5777824abb..a625cdbc20 100755
--- a/src/KOKKOS/fix_nh_kokkos.h
+++ b/src/KOKKOS/fix_nh_kokkos.h
@@ -85,10 +85,11 @@ class FixNHKokkos : public FixNH {
 
 E: Cannot (yet) use rigid bodies with fix nh and Kokkos
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Fix npt/nph has tilted box too far in one step - periodic cell is too far from equilibrium state
 
-UNDOCUMENTED
+Self-explanatory.  The change in the box tilt is too extreme
+on a short timescale.
 
 */
diff --git a/src/KOKKOS/fix_nph_kokkos.h b/src/KOKKOS/fix_nph_kokkos.h
index 04519ddbab..f555814a3a 100755
--- a/src/KOKKOS/fix_nph_kokkos.h
+++ b/src/KOKKOS/fix_nph_kokkos.h
@@ -42,10 +42,10 @@ class FixNPHKokkos : public FixNHKokkos<DeviceType> {
 
 E: Temperature control can not be used with fix nph
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Pressure control must be used with fix nph
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/fix_npt_kokkos.h b/src/KOKKOS/fix_npt_kokkos.h
index e902e955e7..3d23fd9d8f 100755
--- a/src/KOKKOS/fix_npt_kokkos.h
+++ b/src/KOKKOS/fix_npt_kokkos.h
@@ -42,10 +42,10 @@ class FixNPTKokkos : public FixNHKokkos<DeviceType> {
 
 E: Temperature control must be used with fix npt
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Pressure control must be used with fix npt
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/fix_nvt_kokkos.h b/src/KOKKOS/fix_nvt_kokkos.h
index decf314db6..4084b4f032 100755
--- a/src/KOKKOS/fix_nvt_kokkos.h
+++ b/src/KOKKOS/fix_nvt_kokkos.h
@@ -43,10 +43,10 @@ class FixNVTKokkos : public FixNHKokkos<DeviceType> {
 
 E: Temperature control must be used with fix nvt
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Pressure control can not be used with fix nvt
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/kokkos.h b/src/KOKKOS/kokkos.h
index 20d38da21e..ffac06e874 100644
--- a/src/KOKKOS/kokkos.h
+++ b/src/KOKKOS/kokkos.h
@@ -57,7 +57,7 @@ One or more GPUs must be used when Kokkos is compiled for CUDA.
 
 E: Must use Kokkos half/thread or full neighbor list with threads or GPUs
 
-Using Kokkos half neighbor list with threading is not allowed.
+Using Kokkos half-neighbor lists with threading is not allowed.
 
 E: Illegal ... command
 
diff --git a/src/KOKKOS/pair_buck_coul_cut_kokkos.h b/src/KOKKOS/pair_buck_coul_cut_kokkos.h
index 4cca6cb85a..89730e32e0 100644
--- a/src/KOKKOS/pair_buck_coul_cut_kokkos.h
+++ b/src/KOKKOS/pair_buck_coul_cut_kokkos.h
@@ -133,14 +133,16 @@ class PairBuckCoulCutKokkos : public PairBuckCoulCut {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with buck/coul/cut/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_buck_coul_long_kokkos.h b/src/KOKKOS/pair_buck_coul_long_kokkos.h
index df2c57c4b0..04586bd1a3 100644
--- a/src/KOKKOS/pair_buck_coul_long_kokkos.h
+++ b/src/KOKKOS/pair_buck_coul_long_kokkos.h
@@ -149,14 +149,16 @@ class PairBuckCoulLongKokkos : public PairBuckCoulLong {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with buck/coul/long/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_coul_debye_kokkos.h b/src/KOKKOS/pair_coul_debye_kokkos.h
index d0a9997666..4007108588 100644
--- a/src/KOKKOS/pair_coul_debye_kokkos.h
+++ b/src/KOKKOS/pair_coul_debye_kokkos.h
@@ -134,14 +134,16 @@ class PairCoulDebyeKokkos : public PairCoulDebye {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with coul/debye/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_coul_long_kokkos.h b/src/KOKKOS/pair_coul_long_kokkos.h
index 5a5ee63a0a..af38686d68 100644
--- a/src/KOKKOS/pair_coul_long_kokkos.h
+++ b/src/KOKKOS/pair_coul_long_kokkos.h
@@ -153,14 +153,16 @@ class PairCoulLongKokkos : public PairCoulLong {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with buck/coul/long/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_eam_alloy_kokkos.h b/src/KOKKOS/pair_eam_alloy_kokkos.h
index 65ad14303f..6d6f1926e5 100755
--- a/src/KOKKOS/pair_eam_alloy_kokkos.h
+++ b/src/KOKKOS/pair_eam_alloy_kokkos.h
@@ -178,22 +178,24 @@ class PairEAMAlloyKokkos : public PairEAM {
 
 E: Cannot use chosen neighbor list style with pair eam/kk/alloy
 
-That style is not supported by Kokkos.
+Self-explanatory.
 
 E: Incorrect args for pair coefficients
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script or data file.
 
 E: No matching element in EAM potential file
 
-UNDOCUMENTED
+The EAM potential file does not contain elements that match the
+requested elements.
 
 E: Cannot open EAM potential file %s
 
-UNDOCUMENTED
+The specified EAM potential file cannot be opened.  Check that the
+path and name are correct.
 
 E: Incorrect element names in EAM potential file
 
-UNDOCUMENTED
+The element names in the EAM file do not match those requested.
 
 */
diff --git a/src/KOKKOS/pair_eam_fs_kokkos.h b/src/KOKKOS/pair_eam_fs_kokkos.h
index 0ee514a6d8..6049c3eaaf 100755
--- a/src/KOKKOS/pair_eam_fs_kokkos.h
+++ b/src/KOKKOS/pair_eam_fs_kokkos.h
@@ -178,22 +178,24 @@ class PairEAMFSKokkos : public PairEAM {
 
 E: Cannot use chosen neighbor list style with pair eam/kk/fs
 
-That style is not supported by Kokkos.
+Self-explanatory.
 
 E: Incorrect args for pair coefficients
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script or data file.
 
 E: No matching element in EAM potential file
 
-UNDOCUMENTED
+The EAM potential file does not contain elements that match the
+requested elements.
 
 E: Cannot open EAM potential file %s
 
-UNDOCUMENTED
+The specified EAM potential file cannot be opened.  Check that the
+path and name are correct.
 
 E: Incorrect element names in EAM potential file
 
-UNDOCUMENTED
+The element names in the EAM file do not match those requested.
 
 */
diff --git a/src/KOKKOS/pair_lj_charmm_coul_charmm_implicit_kokkos.h b/src/KOKKOS/pair_lj_charmm_coul_charmm_implicit_kokkos.h
index 458306875c..431aca589f 100644
--- a/src/KOKKOS/pair_lj_charmm_coul_charmm_implicit_kokkos.h
+++ b/src/KOKKOS/pair_lj_charmm_coul_charmm_implicit_kokkos.h
@@ -150,14 +150,16 @@ class PairLJCharmmCoulCharmmImplicitKokkos : public PairLJCharmmCoulCharmmImplic
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/charmm/coul/charmm/implicit/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_charmm_coul_charmm_kokkos.h b/src/KOKKOS/pair_lj_charmm_coul_charmm_kokkos.h
index a501961c37..9dc7914d3d 100644
--- a/src/KOKKOS/pair_lj_charmm_coul_charmm_kokkos.h
+++ b/src/KOKKOS/pair_lj_charmm_coul_charmm_kokkos.h
@@ -150,14 +150,16 @@ class PairLJCharmmCoulCharmmKokkos : public PairLJCharmmCoulCharmm {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/charmm/coul/charmm/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_charmm_coul_long_kokkos.h b/src/KOKKOS/pair_lj_charmm_coul_long_kokkos.h
index e74aee1284..8f50722e01 100644
--- a/src/KOKKOS/pair_lj_charmm_coul_long_kokkos.h
+++ b/src/KOKKOS/pair_lj_charmm_coul_long_kokkos.h
@@ -149,10 +149,10 @@ class PairLJCharmmCoulLongKokkos : public PairLJCharmmCoulLong {
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/charmm/coul/long/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_class2_coul_cut_kokkos.h b/src/KOKKOS/pair_lj_class2_coul_cut_kokkos.h
index 5cfacd2ec2..a1d8a8bded 100644
--- a/src/KOKKOS/pair_lj_class2_coul_cut_kokkos.h
+++ b/src/KOKKOS/pair_lj_class2_coul_cut_kokkos.h
@@ -129,14 +129,16 @@ class PairLJClass2CoulCutKokkos : public PairLJClass2CoulCut {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/class2/coul/cut/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_class2_coul_long_kokkos.h b/src/KOKKOS/pair_lj_class2_coul_long_kokkos.h
index 98e0563989..72b0b8609e 100644
--- a/src/KOKKOS/pair_lj_class2_coul_long_kokkos.h
+++ b/src/KOKKOS/pair_lj_class2_coul_long_kokkos.h
@@ -146,14 +146,16 @@ class PairLJClass2CoulLongKokkos : public PairLJClass2CoulLong {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/class2/coul/long/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_class2_kokkos.h b/src/KOKKOS/pair_lj_class2_kokkos.h
index 457a663e7a..8dcabe5b0c 100644
--- a/src/KOKKOS/pair_lj_class2_kokkos.h
+++ b/src/KOKKOS/pair_lj_class2_kokkos.h
@@ -123,14 +123,16 @@ class PairLJClass2Kokkos : public PairLJClass2 {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/class2/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_cut_coul_debye_kokkos.h b/src/KOKKOS/pair_lj_cut_coul_debye_kokkos.h
index ac32decb10..7d4527cb7f 100644
--- a/src/KOKKOS/pair_lj_cut_coul_debye_kokkos.h
+++ b/src/KOKKOS/pair_lj_cut_coul_debye_kokkos.h
@@ -130,14 +130,16 @@ class PairLJCutCoulDebyeKokkos : public PairLJCutCoulDebye {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/cut/coul/debye/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_cut_coul_dsf_kokkos.h b/src/KOKKOS/pair_lj_cut_coul_dsf_kokkos.h
index 7c85a8c1a2..6272bfca35 100644
--- a/src/KOKKOS/pair_lj_cut_coul_dsf_kokkos.h
+++ b/src/KOKKOS/pair_lj_cut_coul_dsf_kokkos.h
@@ -129,10 +129,10 @@ class PairLJCutCoulDSFKokkos : public PairLJCutCoulDSF {
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/cut/coul/cut/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_expand_kokkos.h b/src/KOKKOS/pair_lj_expand_kokkos.h
index f7101fa963..172ccaae73 100644
--- a/src/KOKKOS/pair_lj_expand_kokkos.h
+++ b/src/KOKKOS/pair_lj_expand_kokkos.h
@@ -124,14 +124,16 @@ class PairLJExpandKokkos : public PairLJExpand {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/expand/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_gromacs_coul_gromacs_kokkos.h b/src/KOKKOS/pair_lj_gromacs_coul_gromacs_kokkos.h
index 737e140367..492ef0c369 100644
--- a/src/KOKKOS/pair_lj_gromacs_coul_gromacs_kokkos.h
+++ b/src/KOKKOS/pair_lj_gromacs_coul_gromacs_kokkos.h
@@ -150,14 +150,16 @@ class PairLJGromacsCoulGromacsKokkos : public PairLJGromacsCoulGromacs {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/gromacs/coul/gromacs/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_lj_gromacs_kokkos.h b/src/KOKKOS/pair_lj_gromacs_kokkos.h
index aeb2f814d0..bfe752e93f 100644
--- a/src/KOKKOS/pair_lj_gromacs_kokkos.h
+++ b/src/KOKKOS/pair_lj_gromacs_kokkos.h
@@ -152,14 +152,16 @@ class PairLJGromacsKokkos : public PairLJGromacs {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Cannot use Kokkos pair style with rRESPA inner/middle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use chosen neighbor list style with lj/gromacs/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_sw_kokkos.h b/src/KOKKOS/pair_sw_kokkos.h
index e8fd39f6e1..cec240e064 100755
--- a/src/KOKKOS/pair_sw_kokkos.h
+++ b/src/KOKKOS/pair_sw_kokkos.h
@@ -149,6 +149,6 @@ class PairSWKokkos : public PairSW {
 
 E: Cannot use chosen neighbor list style with pair sw/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_tersoff_kokkos.h b/src/KOKKOS/pair_tersoff_kokkos.h
index 768d6b7669..c810a052dc 100755
--- a/src/KOKKOS/pair_tersoff_kokkos.h
+++ b/src/KOKKOS/pair_tersoff_kokkos.h
@@ -219,6 +219,6 @@ class PairTersoffKokkos : public PairTersoff {
 
 E: Cannot use chosen neighbor list style with tersoff/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_tersoff_mod_kokkos.h b/src/KOKKOS/pair_tersoff_mod_kokkos.h
index f74120ee32..07a76b4e66 100755
--- a/src/KOKKOS/pair_tersoff_mod_kokkos.h
+++ b/src/KOKKOS/pair_tersoff_mod_kokkos.h
@@ -219,6 +219,6 @@ class PairTersoffMODKokkos : public PairTersoffMOD {
 
 E: Cannot use chosen neighbor list style with tersoff/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/KOKKOS/pair_tersoff_zbl_kokkos.h b/src/KOKKOS/pair_tersoff_zbl_kokkos.h
index 54098e1bb8..d580634197 100755
--- a/src/KOKKOS/pair_tersoff_zbl_kokkos.h
+++ b/src/KOKKOS/pair_tersoff_zbl_kokkos.h
@@ -230,10 +230,10 @@ class PairTersoffZBLKokkos : public PairTersoffZBL {
 
 E: Pair tersoff/zbl/kk requires metal or real units
 
-UNDOCUMENTED
+This is a current restriction of this pair potential.
 
 E: Cannot use chosen neighbor list style with tersoff/zbl/kk
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/MANYBODY/pair_bop.h b/src/MANYBODY/pair_bop.h
index dca77b6031..a0408d55dd 100644
--- a/src/MANYBODY/pair_bop.h
+++ b/src/MANYBODY/pair_bop.h
@@ -284,6 +284,6 @@ path and name are correct.
 
 E: Incorrect table format check for element types
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/MANYBODY/pair_polymorphic.cpp b/src/MANYBODY/pair_polymorphic.cpp
index d855ba7010..110c86ab39 100755
--- a/src/MANYBODY/pair_polymorphic.cpp
+++ b/src/MANYBODY/pair_polymorphic.cpp
@@ -764,7 +764,7 @@ void PairPolymorphic::setup_params()
 //   for debugging, call write_tables() to check the tabular functions 
 //   if (comm->me == 0) {
 //     write_tables(51);
-//     error->all(FLERR,"Test potential tables");
+//     error->Xall(FLERR,"Test potential tables");
 //   }
 }  
 
diff --git a/src/MANYBODY/pair_polymorphic.h b/src/MANYBODY/pair_polymorphic.h
index 4c70ca7630..9b7fe761bb 100755
--- a/src/MANYBODY/pair_polymorphic.h
+++ b/src/MANYBODY/pair_polymorphic.h
@@ -322,38 +322,39 @@ class PairPolymorphic : public Pair {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Incorrect args for pair coefficients
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script or data file.
 
 E: Pair style polymorphic requires atom IDs
 
-UNDOCUMENTED
+This is a requirement to use the polymorphic potential.
 
 E: Pair style polymorphic requires newton pair on
 
-UNDOCUMENTED
+See the newton command.  This is a restriction to use the polymorphic
+potential.
 
 E: All pair coeffs are not set
 
-UNDOCUMENTED
+All pair coefficients must be set in the data file or by the
+pair_coeff command before running a simulation.
 
 E: Cannot open polymorphic potential file %s
 
-UNDOCUMENTED
+The specified polymorphic potential file cannot be opened.  Check that
+the path and name are correct.
 
 E: Incorrect number of elements in potential file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Element not defined in potential file
 
-UNDOCUMENTED
-
-E: Test potential tables
-
-UNDOCUMENTED
+The specified element is not in the potential file.
 
 */
diff --git a/src/MC/fix_atom_swap.h b/src/MC/fix_atom_swap.h
index 1c411859a3..25208a2b5a 100644
--- a/src/MC/fix_atom_swap.h
+++ b/src/MC/fix_atom_swap.h
@@ -135,7 +135,7 @@ Self-explanatory.
 
 E: All atoms of a swapped type must have same charge.
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot do atom/swap on atoms in atom_modify first group
 
diff --git a/src/MC/fix_gcmc.h b/src/MC/fix_gcmc.h
index 7f6cd6c5c9..82b4733587 100644
--- a/src/MC/fix_gcmc.h
+++ b/src/MC/fix_gcmc.h
@@ -180,7 +180,7 @@ Self-explanatory.
 
 E: Fix gcmc molecule has charges, but atom style does not
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Fix gcmc molecule template ID must be same as atom_style template ID
 
@@ -189,7 +189,7 @@ not in that template.
 
 E: Fix gcmc atom has charge, but atom style does not
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use fix gcmc shake and not molecule
 
@@ -267,15 +267,16 @@ than or equal to zero.
 
 E: Cannot do GCMC on atoms in atom_modify first group
 
-UNDOCUMENTED
+This is a restriction due to the way atoms are organized in a list to
+enable the atom_modify first command.
 
 E: Could not find specified fix gcmc group ID
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Fix gcmc put atom outside box
 
-UNDOCUMENTED
+This should not normally happen.  Contact the developers.
 
 E: Fix gcmc ran out of available molecule IDs
 
@@ -289,9 +290,4 @@ E: Too many total atoms
 
 See the setting for bigint in the src/lmptype.h file.
 
-U: Cannot do gcmc on atoms in atom_modify first group
-
-This is a restriction due to the way atoms are organized in a list to
-enable the atom_modify first command.
-
 */
diff --git a/src/MISC/fix_deposit.h b/src/MISC/fix_deposit.h
index 8cf19d128d..76fc4f89e7 100644
--- a/src/MISC/fix_deposit.h
+++ b/src/MISC/fix_deposit.h
@@ -155,7 +155,9 @@ Self-explanatory.
 
 W: Fix deposit near setting < possible overlap separation %g
 
-UNDOCUMENTED
+This test is performed for finite size particles with a diameter, not
+for point particles.  The near setting is smaller than the particle
+diameter which can lead to overlaps.
 
 W: Particle deposition was unsuccessful
 
diff --git a/src/RIGID/fix_rigid_small.h b/src/RIGID/fix_rigid_small.h
index 22f8665ac7..fb9ae67098 100644
--- a/src/RIGID/fix_rigid_small.h
+++ b/src/RIGID/fix_rigid_small.h
@@ -258,7 +258,8 @@ incorrect.
 
 W: Cannot count rigid body degrees-of-freedom before bodies are fully initialized
 
-UNDOCUMENTED
+This means the temperature associated with the rigid bodies may be
+incorrect on this timestep.
 
 W: Computing temperature of portions of rigid bodies
 
@@ -273,7 +274,7 @@ Image flags for non-periodic dimensions should not be set.
 
 E: One or more rigid bodies are a single particle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Inconsistent use of finite-size particles by molecule template molecules
 
@@ -320,9 +321,4 @@ cutoff command to insure ghost atoms are acquired from far enough away
 to encompass the max distance printed when the fix rigid/small command
 was invoked.
 
-U: Cannot count rigid body degrees-of-freedom before bodies are fully initialized h
-
-This means the temperature associated with the rigid bodies may be
-incorrect on this timestep.
-
 */
diff --git a/src/atom.h b/src/atom.h
index 4ff4d9c1c5..d5e3ba10a3 100644
--- a/src/atom.h
+++ b/src/atom.h
@@ -362,27 +362,29 @@ Self-explanatory.
 
 E: One or more Atom IDs is negative
 
-UNDOCUMENTED
+Atom IDs must be positive integers.
 
 E: One or more atom IDs is too big
 
-UNDOCUMENTED
+The limit on atom IDs is set by the SMALLBIG, BIGBIG, SMALLSMALL
+setting in your Makefile.  See Section_start 2.2 of the manual for
+more details.
 
 E: One or more atom IDs is zero
 
-UNDOCUMENTED
+Either all atoms IDs must be zero or none of them.
 
 E: Non-zero atom IDs with atom_modify id = no
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: All atom IDs = 0 but atom_modify id = yes
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Duplicate atom IDs exist
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: New atom IDs exceed maximum allowed ID
 
@@ -395,7 +397,7 @@ the atom style.
 
 E: Invalid atom type in Atoms section of data file
 
-UNDOCUMENTED
+Atom types can be no larger than defined Ntypes.
 
 E: Incorrect velocity format in data file
 
@@ -507,22 +509,4 @@ E: Too many atom sorting bins
 This is likely due to an immense simulation box that has blown up
 to a large size.
 
-U: Atom ID is negative
-
-Self-explanatory.
-
-U: Atom ID is too big
-
-The limit on atom IDs is set by the SMALLBIG, BIGBIG, SMALLSMALL
-setting in your Makefile.  See Section_start 2.2 of the manual for
-more details.
-
-U: Atom ID is zero
-
-Either all atoms IDs must be zero or none of them.
-
-U: Not all atom IDs are 0
-
-Either all atoms IDs must be zero or none of them.
-
 */
diff --git a/src/atom_vec_body.h b/src/atom_vec_body.h
index fd0199ee13..9ab935f91d 100644
--- a/src/atom_vec_body.h
+++ b/src/atom_vec_body.h
@@ -151,6 +151,6 @@ Self-explanatory.
 
 E: Assigning quat to non-body atom
 
-UNDOCUMENTED
+Self-explanatory.
 
 */
diff --git a/src/comm.cpp b/src/comm.cpp
index 073166d229..60d734d759 100644
--- a/src/comm.cpp
+++ b/src/comm.cpp
@@ -265,7 +265,7 @@ void Comm::modify_params(int narg, char **arg)
     } else if (strcmp(arg[iarg],"cutoff") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal comm_modify command");
       if (mode == MULTI)
-        error->all(FLERR,"Use cutoff/multi flag to set cutoff in multi mode");
+        error->all(FLERR,"Use cutoff/multi keyword to set cutoff in multi mode");
       cutghostuser = force->numeric(FLERR,arg[iarg+1]);
       if (cutghostuser < 0.0)
         error->all(FLERR,"Invalid cutoff in comm_modify command");
@@ -274,7 +274,7 @@ void Comm::modify_params(int narg, char **arg)
       int i,nlo,nhi;
       double cut;
       if (mode == SINGLE)
-        error->all(FLERR,"Use cutoff flag to set cutoff in single mode");
+        error->all(FLERR,"Use cutoff keyword to set cutoff in single mode");
       if (domain->box_exist == 0)
         error->all(FLERR,
                    "Cannot set cutoff/multi before simulation box is defined");
diff --git a/src/comm.h b/src/comm.h
index 90f3cd6d35..f6404868df 100644
--- a/src/comm.h
+++ b/src/comm.h
@@ -163,21 +163,21 @@ E: Comm_modify group != atom_modify first group
 
 Self-explanatory.
 
-E: Use cutoff/multi flag to set cutoff in multi mode
+E: Use cutoff/multi keyword to set cutoff in multi mode
 
-UNDOCUMENTED
+Mode is multi so cutoff keyword cannot be used.
 
 E: Invalid cutoff in comm_modify command
 
 Specified cutoff must be >= 0.0.
 
-E: Use cutoff flag to set cutoff in single mode
+E: Use cutoff keyword to set cutoff in single mode
 
-UNDOCUMENTED
+Mode is single so cutoff/multi keyword cannot be used.
 
 E: Cannot set cutoff/multi before simulation box is defined
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Specified processors != physical processors
 
diff --git a/src/compute_chunk_atom.h b/src/compute_chunk_atom.h
index b8e76a924c..cbec221048 100644
--- a/src/compute_chunk_atom.h
+++ b/src/compute_chunk_atom.h
@@ -155,15 +155,15 @@ That discard option only applies to the binning styles.
 
 E: Compute chunk/atom sphere z origin must be 0.0 for 2d
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Compute chunk/atom cylinder axis must be z for 2d
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Compute ID for compute chunk /atom does not exist
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Compute chunk/atom compute does not calculate per-atom values
 
@@ -248,11 +248,11 @@ The lo/hi values are inconsistent.
 
 E: Compute chunk/atom bin/sphere radius is too large for periodic box
 
-UNDOCUMENTED
+Radius cannot be bigger than 1/2 of any periodic dimention.
 
 E: Compute chunk/atom bin/cylinder radius is too large for periodic box
 
-UNDOCUMENTED
+Radius cannot be bigger than 1/2 of a non-axis  periodic dimention.
 
 E: Cannot use compute chunk/atom bin z for 2d model
 
diff --git a/src/compute_hexorder_atom.h b/src/compute_hexorder_atom.h
index 0508da7d3f..84c80abc57 100644
--- a/src/compute_hexorder_atom.h
+++ b/src/compute_hexorder_atom.h
@@ -66,7 +66,7 @@ Self-explantory.
 
 E: Compute hexorder/atom cutoff is longer than pairwise cutoff
 
-UNDOCUMENTED
+Cannot compute order parameter beyond cutoff.
 
 W: More than one compute hexorder/atom
 
diff --git a/src/compute_msd_chunk.h b/src/compute_msd_chunk.h
index 54f149784e..216fde33bc 100644
--- a/src/compute_msd_chunk.h
+++ b/src/compute_msd_chunk.h
@@ -78,7 +78,7 @@ The style of the specified compute is not chunk/atom.
 
 E: Could not find compute msd/chunk fix ID
 
-UNDOCUMENTED
+The compute creates an internal fix, which has been deleted.
 
 E: Compute msd/chunk nchunk is not static
 
diff --git a/src/compute_orientorder_atom.h b/src/compute_orientorder_atom.h
index 93f9f7b4af..9c5ec14f56 100644
--- a/src/compute_orientorder_atom.h
+++ b/src/compute_orientorder_atom.h
@@ -75,7 +75,7 @@ Self-explantory.
 
 E: Compute orientorder/atom cutoff is longer than pairwise cutoff
 
-UNDOCUMENTED
+Cannot compute order parameter beyond cutoff.
 
 W: More than one compute orientorder/atom
 
diff --git a/src/compute_temp.h b/src/compute_temp.h
index 3313965303..1550ae7a99 100644
--- a/src/compute_temp.h
+++ b/src/compute_temp.h
@@ -54,6 +54,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_chunk.h b/src/compute_temp_chunk.h
index a4ddf8f420..d47d6d79ec 100644
--- a/src/compute_temp_chunk.h
+++ b/src/compute_temp_chunk.h
@@ -108,6 +108,7 @@ The style of the specified compute is not chunk/atom.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_com.h b/src/compute_temp_com.h
index 1d90028db2..47587ceccc 100644
--- a/src/compute_temp_com.h
+++ b/src/compute_temp_com.h
@@ -60,6 +60,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_deform.h b/src/compute_temp_deform.h
index c1f5469008..33ca83c73d 100644
--- a/src/compute_temp_deform.h
+++ b/src/compute_temp_deform.h
@@ -70,6 +70,7 @@ compute temp/deform in this case.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_partial.h b/src/compute_temp_partial.h
index a66c8f0fd2..8a5c260db1 100644
--- a/src/compute_temp_partial.h
+++ b/src/compute_temp_partial.h
@@ -67,6 +67,7 @@ Self-explanatory.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_profile.h b/src/compute_temp_profile.h
index 4890a3f252..d78e5396d6 100644
--- a/src/compute_temp_profile.h
+++ b/src/compute_temp_profile.h
@@ -85,6 +85,7 @@ Self-explanatory.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_ramp.h b/src/compute_temp_ramp.h
index ef6432146c..0e10e519cb 100644
--- a/src/compute_temp_ramp.h
+++ b/src/compute_temp_ramp.h
@@ -65,6 +65,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_region.h b/src/compute_temp_region.h
index 08b11641a7..95194d7fdf 100644
--- a/src/compute_temp_region.h
+++ b/src/compute_temp_region.h
@@ -65,6 +65,7 @@ Self-explanatory.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/compute_temp_sphere.h b/src/compute_temp_sphere.h
index 3b7418642d..ae72fe2684 100644
--- a/src/compute_temp_sphere.h
+++ b/src/compute_temp_sphere.h
@@ -82,6 +82,7 @@ compute.
 
 E: Temperature compute degrees of freedom < 0
 
-UNDOCUMENTED
+This should not happen if you are calculating the temperature
+on a valid set of atoms.
 
 */
diff --git a/src/delete_atoms.h b/src/delete_atoms.h
index 6bda837598..6fc2ea1f90 100644
--- a/src/delete_atoms.h
+++ b/src/delete_atoms.h
@@ -113,10 +113,6 @@ molecule template.
 
 E: Delete_atoms mol yes requires atom attribute molecule
 
-UNDOCUMENTED
-
-U: Cannot delete_atoms mol yes for non-molecular systems
-
-Self-explanatory.
+Cannot use this option with a non-molecular system.
 
 */
diff --git a/src/displace_atoms.h b/src/displace_atoms.h
index 239627b1b0..c303332900 100644
--- a/src/displace_atoms.h
+++ b/src/displace_atoms.h
@@ -81,10 +81,10 @@ The command options you have used caused atoms to be lost.
 
 E: Variable name for displace_atoms does not exist
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Variable for displace_atoms is invalid style
 
-UNDOCUMENTED
+It must be an equal-style or atom-style variable.
 
 */
diff --git a/src/dump_image.h b/src/dump_image.h
index e17e73c7a3..64846e3e4b 100644
--- a/src/dump_image.h
+++ b/src/dump_image.h
@@ -137,15 +137,15 @@ Self-explanatory.
 
 E: Dump image line requires atom style line
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Dump image tri requires atom style tri
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Dump image body yes requires atom style body
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Dump image requires one snapshot per file
 
diff --git a/src/fix_ave_chunk.h b/src/fix_ave_chunk.h
index b882923876..18622699de 100644
--- a/src/fix_ave_chunk.h
+++ b/src/fix_ave_chunk.h
@@ -89,7 +89,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: No values in fix ave/chunk command
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot open fix ave/chunk file %s
 
@@ -166,7 +166,7 @@ The specified conpute is not for a compute chunk/atom command.
 
 E: Error writing file header
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Fix for fix ave/chunk not computed at compatible time
 
@@ -180,6 +180,6 @@ fix needs to process.
 
 E: Error writing averaged chunk data
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 */
diff --git a/src/fix_ave_correlate.h b/src/fix_ave_correlate.h
index 2b5bb46594..6c592923a3 100644
--- a/src/fix_ave_correlate.h
+++ b/src/fix_ave_correlate.h
@@ -127,7 +127,7 @@ Self-explanatory.
 
 E: Error writing file header
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Invalid timestep reset for fix ave/correlate
 
@@ -136,6 +136,6 @@ fix needs to process.
 
 E: Error writing out correlation data
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 */
diff --git a/src/fix_ave_histo.h b/src/fix_ave_histo.h
index fbf3dfc19d..44109b8f17 100644
--- a/src/fix_ave_histo.h
+++ b/src/fix_ave_histo.h
@@ -215,7 +215,7 @@ Self-explanatory.
 
 E: Error writing file header
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Invalid timestep reset for fix ave/histo
 
@@ -224,7 +224,7 @@ fix needs to process.
 
 E: Error writing out histogram data
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Cannot open fix ave/histo file %s
 
diff --git a/src/fix_ave_histo_weight.h b/src/fix_ave_histo_weight.h
index 6de08d8158..2eba1a0468 100644
--- a/src/fix_ave_histo_weight.h
+++ b/src/fix_ave_histo_weight.h
@@ -52,7 +52,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: Fix ave/histo/weight value and weight vector lengths do not match
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid timestep reset for fix ave/histo
 
@@ -61,141 +61,6 @@ fix needs to process.
 
 E: Error writing out histogram data
 
-UNDOCUMENTED
-
-U: Compute ID for fix ave/histo does not exist
-
-Self-explanatory.
-
-U: Fix ID for fix ave/histo does not exist
-
-Self-explanatory.
-
-U: Fix ave/histo input is invalid compute
-
-Self-explanatory.
-
-U: Fix ave/histo input is invalid fix
-
-Self-explanatory.
-
-U: Fix ave/histo input is invalid variable
-
-Self-explanatory.
-
-U: Fix ave/histo inputs are not all global, peratom, or local
-
-All inputs in a single fix ave/histo command must be of the
-same style.
-
-U: Fix ave/histo cannot input per-atom values in scalar mode
-
-Self-explanatory.
-
-U: Fix ave/histo cannot input local values in scalar mode
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a global scalar
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a global vector
-
-Self-explanatory.
-
-U: Fix ave/histo compute vector is accessed out-of-range
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a global array
-
-Self-explanatory.
-
-U: Fix ave/histo compute array is accessed out-of-range
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate per-atom values
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a per-atom vector
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a per-atom array
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate local values
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a local vector
-
-Self-explanatory.
-
-U: Fix ave/histo compute does not calculate a local array
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a global scalar
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a global vector
-
-Self-explanatory.
-
-U: Fix ave/histo fix vector is accessed out-of-range
-
-Self-explanatory.
-
-U: Fix for fix ave/histo not computed at compatible time
-
-Fixes generate their values on specific timesteps.  Fix ave/histo is
-requesting a value on a non-allowed timestep.
-
-U: Fix ave/histo fix does not calculate a global array
-
-Self-explanatory.
-
-U: Fix ave/histo fix array is accessed out-of-range
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate per-atom values
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a per-atom vector
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a per-atom array
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate local values
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a local vector
-
-Self-explanatory.
-
-U: Fix ave/histo fix does not calculate a local array
-
-Self-explanatory.
-
-U: Variable name for fix ave/histo does not exist
-
-Self-explanatory.
-
-U: Cannot open fix ave/histo file %s
-
-The specified file cannot be opened.  Check that the path and name are
-correct.
+Something in the output to the file triggered an error.
 
 */
diff --git a/src/fix_ave_time.h b/src/fix_ave_time.h
index 4c1f2d281f..98b665140c 100644
--- a/src/fix_ave_time.h
+++ b/src/fix_ave_time.h
@@ -90,7 +90,7 @@ command-line option when running LAMMPS to see the offending line.
 
 E: No values in fix ave/time command
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Compute ID for fix ave/time does not exist
 
@@ -171,7 +171,7 @@ Variables produce scalar values.
 
 E: Error writing file header
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Fix ave/time cannot set output array intensive/extensive from these inputs
 
@@ -186,7 +186,7 @@ fix needs to process.
 
 E: Error writing out time averaged data
 
-UNDOCUMENTED
+Something in the output to the file triggered an error.
 
 E: Fix ave/time columns are inconsistent lengths
 
diff --git a/src/fix_move.h b/src/fix_move.h
index f8fe89fa72..accc23c7f7 100644
--- a/src/fix_move.h
+++ b/src/fix_move.h
@@ -129,12 +129,4 @@ E: Resetting timestep size is not allowed with fix move
 
 This is because fix move is moving atoms based on elapsed time.
 
-U: Fix move does not update angular momentum
-
-Atoms store this quantity, but fix move does not (yet) update it.
-
-U: Fix move does not update quaternions
-
-Atoms store this quantity, but fix move does not (yet) update it.
-
 */
diff --git a/src/fix_nh.h b/src/fix_nh.h
index dedfc3bf00..7227a22968 100644
--- a/src/fix_nh.h
+++ b/src/fix_nh.h
@@ -214,11 +214,11 @@ Settings for coupled dimensions must be the same.
 
 E: Using update dipole flag requires atom style sphere
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Using update dipole flag requires atom attribute mu
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Fix nvt/npt/nph damping parameters must be > 0.0
 
diff --git a/src/fix_nve_limit.h b/src/fix_nve_limit.h
index 2a13b03947..aefececd72 100644
--- a/src/fix_nve_limit.h
+++ b/src/fix_nve_limit.h
@@ -58,10 +58,7 @@ command-line option when running LAMMPS to see the offending line.
 
 W: Should not use fix nve/limit with fix shake or fix rattle
 
-UNDOCUMENTED
-
-U: Should not use fix nve/limit with fix shake
-
-This will lead to invalid constraint forces in the SHAKE computation.
+This will lead to invalid constraint forces in the SHAKE/RATTLE
+computation.
 
 */
diff --git a/src/fix_nve_sphere.h b/src/fix_nve_sphere.h
index 04da95b709..10a22be702 100644
--- a/src/fix_nve_sphere.h
+++ b/src/fix_nve_sphere.h
@@ -55,14 +55,10 @@ Self-explanatory.
 
 E: Fix nve/sphere dipole requires atom attribute mu
 
-UNDOCUMENTED
+An atom style with this attribute is needed.
 
 E: Fix nve/sphere requires extended particles
 
 This fix can only be used for particles of a finite size.
 
-U: Fix nve/sphere requires atom attribute mu
-
-An atom style with this attribute is needed.
-
 */
diff --git a/src/fix_property_atom.h b/src/fix_property_atom.h
index 385125936f..e97b53cd1d 100644
--- a/src/fix_property_atom.h
+++ b/src/fix_property_atom.h
@@ -94,7 +94,7 @@ The name for an integer or floating-point vector must be unique.
 
 W: Fix property/atom mol or charge w/out ghost communication
 
-UNDOCUMENTED
+A model typically needs these properties defined for ghost atoms.
 
 E: Atom style was redefined after using fix property/atom
 
@@ -107,7 +107,7 @@ not have the correct number of values per line.
 
 E: Too few lines in %s section of data file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom ID in %s section of data file
 
diff --git a/src/fix_store.cpp b/src/fix_store.cpp
index c627f1cc79..febdb39fc3 100644
--- a/src/fix_store.cpp
+++ b/src/fix_store.cpp
@@ -44,7 +44,7 @@ FixStore::FixStore(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
 
   if (strcmp(arg[3],"global") == 0) flavor = GLOBAL;
   else if (strcmp(arg[3],"peratom") == 0) flavor = PERATOM;
-  else error->all(FLERR,"Invalid fix store command");
+  else error->all(FLERR,"Illegal fix store command");
 
   // GLOBAL values are always written to restart file
   // PERATOM restart_peratom is set by caller
@@ -54,7 +54,7 @@ FixStore::FixStore(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
     nrow = force->inumeric(FLERR,arg[4]);
     ncol = force->inumeric(FLERR,arg[5]);
     if (nrow <= 0 || ncol <= 0)
-      error->all(FLERR,"Invalid fix store command");
+      error->all(FLERR,"Illegal fix store command");
     vecflag = 0;
     if (ncol == 1) vecflag = 1;
   }
@@ -62,7 +62,7 @@ FixStore::FixStore(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg)
     restart_peratom = force->inumeric(FLERR,arg[4]);
     nvalues = force->inumeric(FLERR,arg[5]);
     if (restart_peratom < 0 or restart_peratom > 1 || nvalues <= 0)
-      error->all(FLERR,"Invalid fix store command");
+      error->all(FLERR,"Illegal fix store command");
     vecflag = 0;
     if (nvalues == 1) vecflag = 1;
   }
diff --git a/src/fix_store.h b/src/fix_store.h
index d0be64d146..9bdfc7d308 100644
--- a/src/fix_store.h
+++ b/src/fix_store.h
@@ -71,8 +71,4 @@ Self-explanatory.  Check the input script syntax and compare to the
 documentation for the command.  You can use -echo screen as a
 command-line option when running LAMMPS to see the offending line.
 
-E: Invalid fix store command
-
-UNDOCUMENTED
-
 */
diff --git a/src/fix_wall_region.h b/src/fix_wall_region.h
index 847cdeff5e..96dd6c17dc 100644
--- a/src/fix_wall_region.h
+++ b/src/fix_wall_region.h
@@ -86,11 +86,7 @@ One of the particles has radius 0.0.
 
 E: Particle outside surface of region used in fix wall/region
 
-UNDOCUMENTED
-
-U: Particle on or inside surface of region used in fix wall/region
-
-Particles must be "exterior" to the region surface in order for
-energy/force to be calculated.
+Particles must be inside the region for energy/force to be calculated.
+A particle outside the region generates an error.
 
 */
diff --git a/src/group.h b/src/group.h
index 423e351c78..47114b1740 100644
--- a/src/group.h
+++ b/src/group.h
@@ -138,7 +138,7 @@ A region ID used in the group command does not exist.
 
 E: Illegal range increment value
 
-UNDOCUMENTED
+The increment must be >= 1.
 
 E: Variable name for group does not exist
 
diff --git a/src/info.cpp b/src/info.cpp
index e2f3eab992..6bfd090b58 100644
--- a/src/info.cpp
+++ b/src/info.cpp
@@ -477,13 +477,13 @@ bool Info::is_active(const char *category, const char *name)
       return (lmp->kokkos && lmp->kokkos->kokkos_exists) ? true : false;
     } else if (strcmp(name,"omp") == 0) {
       return (modify->find_fix("package_omp") >= 0) ? true : false;
-    } else error->all(FLERR,"Unknown name for package category");
+    } else error->all(FLERR,"Unknown name for info package category");
 
   } else if (strcmp(category,"newton") == 0) {
     if (strcmp(name,"pair") == 0) return (force->newton_pair != 0);
     else if (strcmp(name,"bond") == 0) return (force->newton_bond != 0);
     else if (strcmp(name,"any") == 0) return (force->newton != 0);
-    else error->all(FLERR,"Unknown name for newton category");
+    else error->all(FLERR,"Unknown name for info newton category");
 
   } else if (strcmp(category,"pair") == 0) {
     if (force->pair == NULL) return false;
@@ -492,7 +492,7 @@ bool Info::is_active(const char *category, const char *name)
     else if (strcmp(name,"manybody") == 0) return (force->pair->manybody_flag != 0);
     else if (strcmp(name,"tail") == 0) return (force->pair->tail_flag != 0);
     else if (strcmp(name,"shift") == 0) return (force->pair->offset_flag != 0);
-    else error->all(FLERR,"Unknown name for pair category");
+    else error->all(FLERR,"Unknown name for info pair category");
 
   } else if (strcmp(category,"comm_style") == 0) {
     style = commstyles[comm->style];
@@ -514,7 +514,7 @@ bool Info::is_active(const char *category, const char *name)
     style = force->improper_style;
   } else if (strcmp(category,"kspace_style") == 0) {
     style = force->kspace_style;
-  } else error->all(FLERR,"Unknown category for is_active()");
+  } else error->all(FLERR,"Unknown category for info is_active()");
 
   int match = 0;
   if (strcmp(style,name) == 0) match = 1;
@@ -612,7 +612,7 @@ bool Info::is_available(const char *category, const char *name)
         delete[] name_w_suffix;
       }
     }
-  } else error->all(FLERR,"Unknown category for is_available()");
+  } else error->all(FLERR,"Unknown category for info is_available()");
 
   return match ? true : false;
 }
@@ -670,7 +670,7 @@ bool Info::is_defined(const char *category, const char *name)
       if (strcmp(names[i],name) == 0)
         return true;
     }
-  } else error->all(FLERR,"Unknown category for is_defined()");
+  } else error->all(FLERR,"Unknown category for info is_defined()");
 
   return false;
 }
diff --git a/src/info.h b/src/info.h
index 66c13715e8..22906d0473 100644
--- a/src/info.h
+++ b/src/info.h
@@ -43,37 +43,31 @@ class Info : protected Pointers {
 
 W: Ignoring unknown or incorrect info command flag
 
-Self-explanatory. The an unknown argument was given to the info command.
+Self-explanatory.  An unknown argument was given to the info command.
 Compare your input with the documentation.
 
-E: Unknown name for package category
+E: Unknown name for info package category
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: Unknown name for newton category
+E: Unknown name for info newton category
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: Unknown name for pair category
+E: Unknown name for info pair category
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: Unknown category for is_active()
+E: Unknown category info for is_active()
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: Unknown category for is_available()
+E: Unknown category info for is_available()
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: Unknown category for is_defined()
+E: Unknown category info for is_defined()
 
-UNDOCUMENTED
-
-U: Illegal ... command
-
-Self-explanatory.  Check the input script syntax and compare to the
-documentation for the command.  You can use -echo screen as a
-command-line option when running LAMMPS to see the offending line.
+Self-explanatory.
 
 */
diff --git a/src/input.cpp b/src/input.cpp
index a38e91b2d4..a387206241 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -1092,7 +1092,7 @@ char *shell_failed_message(const char* cmd, int errnum)
   const char *errmsg = strerror(errnum);
   int len = strlen(cmd)+strlen(errmsg)+64;
   char *msg = new char[len];
-  sprintf(msg,"shell command '%s' failed with error '%s'", cmd, errmsg);
+  sprintf(msg,"Shell command '%s' failed with error '%s'", cmd, errmsg);
   return msg;
 }
 
@@ -1195,7 +1195,7 @@ void Input::shell()
 
     if (me == 0)
       if (system(work) != 0)
-        error->warning(FLERR,"shell command returned with non-zero status");
+        error->warning(FLERR,"Shell command returned with non-zero status");
   }
 }
 
diff --git a/src/input.h b/src/input.h
index 7ed88f2140..9bdedabe14 100644
--- a/src/input.h
+++ b/src/input.h
@@ -200,13 +200,13 @@ E: Cannot open print file %s
 
 Self-explanatory.
 
-W: shell command '%s' failed with error '%s'
+W: Shell command '%s' failed with error '%s'
 
-UNDOCUMENTED
+Self-explanatory.
 
-W: shell command returned with non-zero status
+W: Shell command returned with non-zero status
 
-UNDOCUMENTED
+This may indicate the shell command did not operate as expected.
 
 E: Angle_coeff command before simulation box is defined
 
diff --git a/src/kspace.h b/src/kspace.h
index 2c14e11b93..5519a8c56f 100644
--- a/src/kspace.h
+++ b/src/kspace.h
@@ -222,7 +222,7 @@ Self-explanatory.
 
 E: System is not charge neutral, net charge = %g
 
-The total charge on all atoms in the system is not 0.0.
+The total charge on all atoms on the system is not 0.0.
 For some KSpace solvers this is an error.
 
 W: System is not charge neutral, net charge = %g
diff --git a/src/molecule.cpp b/src/molecule.cpp
index 8ac2c037ee..dc60b98e8b 100644
--- a/src/molecule.cpp
+++ b/src/molecule.cpp
@@ -461,7 +461,7 @@ void Molecule::read(int flag)
 
   // error checks
 
-  if (natoms < 1) error->all(FLERR,"No or invalid atom count in molecule file");
+  if (natoms < 1) error->all(FLERR,"No count or invalid atom count in molecule file");
   if (nbonds < 0) error->all(FLERR,"Invalid bond count in molecule file");
   if (nangles < 0) error->all(FLERR,"Invalid angle count in molecule file");
   if (ndihedrals < 0)
@@ -1145,7 +1145,7 @@ void Molecule::special_generate()
         atom1 = i;
         atom2 = bond_atom[i][j];
         if (count[atom1] >= maxspecial)
-          error->one(FLERR,"");
+          error->one(FLERR,"Molecule auto special bond generation overflow");
         special[i][count[atom1]++] = atom2;
       }
     }
diff --git a/src/molecule.h b/src/molecule.h
index b6cb9f778d..0bbe684636 100644
--- a/src/molecule.h
+++ b/src/molecule.h
@@ -167,7 +167,9 @@ class Molecule : protected Pointers {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 E: Molecule template ID must be alphanumeric or underscore characters
 
@@ -187,27 +189,27 @@ Self-explanatory.
 
 E: Molecule file requires atom style body
 
-UNDOCUMENTED
+Self-explanatory.
 
-E: No or invalid atom count in molecule file
+E: No count or invalid atom count in molecule file
 
-UNDOCUMENTED
+The number of atoms must be specified.
 
 E: Invalid bond count in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid angle count in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid dihedral count in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid improper count in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule file has bonds but no nbonds setting
 
@@ -235,7 +237,7 @@ The order of the two sections is important.
 
 E: Molecule file has body params but no setting for them
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Unknown section in molecule file
 
@@ -255,23 +257,23 @@ All 3 SHAKE sections are needed.
 
 E: Molecule file has no Body Integers section
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule file has no Body Doubles section
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule natoms must be 1 for body particle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule sizescale must be 1.0 for body particle
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid Coords section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule file z coord must be 0.0 for 2d
 
@@ -279,7 +281,7 @@ Self-explanatory.
 
 E: Invalid Types section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom type in molecule file
 
@@ -287,11 +289,11 @@ Atom types must range from 1 to specified # of types.
 
 E: Invalid Charges section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid Diameters section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom diameter in molecule file
 
@@ -299,7 +301,7 @@ Diameters must be >= 0.0.
 
 E: Invalid Masses section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom mass in molecule file
 
@@ -307,7 +309,7 @@ Masses must be > 0.0.
 
 E: Invalid Bonds section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom ID in Bonds section of molecule file
 
@@ -319,7 +321,7 @@ Self-explanatory.
 
 E: Invalid Angles section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom ID in Angles section of molecule file
 
@@ -331,7 +333,7 @@ Self-explanatory.
 
 E: Invalid Dihedrals section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom ID in dihedrals section of molecule file
 
@@ -343,7 +345,7 @@ Self-explanatory.
 
 E: Invalid Impropers section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid atom ID in impropers section of molecule file
 
@@ -355,7 +357,7 @@ Self-explanatory.
 
 E: Invalid Special Bond Counts section in molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Molecule file special list does not match special count
 
@@ -367,11 +369,7 @@ Self-explanatory.
 
 E: Molecule auto special bond generation overflow
 
-UNDOCUMENTED
-
-E: 
-
-UNDOCUMENTED
+Counts exceed maxspecial setting for other atoms in system.
 
 E: Invalid shake flag in molecule file
 
@@ -391,11 +389,11 @@ Self-explanatory.
 
 E: Too few values in body section of molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Too many values in body section of molecule file
 
-UNDOCUMENTED
+Self-explanatory.
 
 W: Molecule attributes do not match system attributes
 
@@ -424,12 +422,4 @@ E: Cannot open molecule file %s
 The specified file cannot be opened.  Check that the path and name are
 correct.
 
-U: No atom count in molecule file
-
-Self-explanatory.
-
-U: Molecule file has bonds but no special flags
-
-Self-explanatory.
-
 */
diff --git a/src/pair.cpp b/src/pair.cpp
index 016323ffac..89c5bea380 100644
--- a/src/pair.cpp
+++ b/src/pair.cpp
@@ -201,9 +201,9 @@ void Pair::init()
   if (tail_flag && domain->nonperiodic && comm->me == 0)
     error->warning(FLERR,"Using pair tail corrections with nonperiodic system");
   if (!compute_flag && tail_flag)
-    error->warning(FLERR,"Using pair tail corrections with compute set to no");
+    error->warning(FLERR,"Using pair tail corrections with pair_modify compute no");
   if (!compute_flag && offset_flag)
-    error->warning(FLERR,"Using pair potential shift with compute set to no");
+    error->warning(FLERR,"Using pair potential shift with pair_modify compute no");
 
   // for manybody potentials
   // check if bonded exclusions could invalidate the neighbor list
diff --git a/src/pair.h b/src/pair.h
index 662f58bf10..917dfbc700 100644
--- a/src/pair.h
+++ b/src/pair.h
@@ -285,13 +285,13 @@ This is probably a bogus thing to do, since tail corrections are
 computed by integrating the density of a periodic system out to
 infinity.
 
-W: Using pair tail corrections with compute set to no
+W: Using pair tail corrections with pair_modify compute no
 
-UNDOCUMENTED
+The tail corrections will thus not be computed.
 
-W: Using pair potential shift with compute set to no
+W: Using pair potential shift with pair_modify compute no
 
-UNDOCUMENTED
+The shift effects will thus not be computed.
 
 W: Using a manybody potential with bonds/angles/dihedrals and special_bond exclusions
 
diff --git a/src/pair_hybrid.cpp b/src/pair_hybrid.cpp
index f56ff79663..ced2f6f34a 100644
--- a/src/pair_hybrid.cpp
+++ b/src/pair_hybrid.cpp
@@ -471,8 +471,8 @@ void PairHybrid::init_style()
       for (i = 1; i < 4; ++i) {
         if (((force->special_lj[i] == 0.0) || (force->special_lj[i] == 1.0))
             && (force->special_lj[i] != special_lj[istyle][i]))
-          error->all(FLERR,"Pair_modify special setting incompatible with"
-                     " global special_bonds setting");
+          error->all(FLERR,"Pair_modify special setting for pair hybrid "
+		     "incompatible with global special_bonds setting");
       }
     }
 
@@ -481,8 +481,8 @@ void PairHybrid::init_style()
         if (((force->special_coul[i] == 0.0)
              || (force->special_coul[i] == 1.0))
             && (force->special_coul[i] != special_coul[istyle][i]))
-          error->all(FLERR,"Pair_modify special setting incompatible with"
-                     "global special_bonds setting");
+          error->all(FLERR,"Pair_modify special setting for pair hybrid "
+		     "incompatible with global special_bonds setting");
       }
     }
   }
diff --git a/src/pair_hybrid.h b/src/pair_hybrid.h
index b2cfb14f15..56e0c5a7ae 100644
--- a/src/pair_hybrid.h
+++ b/src/pair_hybrid.h
@@ -120,11 +120,8 @@ command.
 
 E: Pair_modify special setting incompatible with global special_bonds setting
 
-UNDOCUMENTED
-
-E: Pair_modify special setting incompatible withglobal special_bonds setting
-
-UNDOCUMENTED
+Cannot override a setting of 0.0 or 1.0 or change a setting between
+0.0 and 1.0.
 
 E: All pair coeffs are not set
 
@@ -144,7 +141,7 @@ that doesn't support it.
 
 E: Pair hybrid single calls do not support per sub-style special bond values
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Unknown pair_modify hybrid sub-style
 
diff --git a/src/read_data.h b/src/read_data.h
index 4317bcdd1a..9402bd18e4 100644
--- a/src/read_data.h
+++ b/src/read_data.h
@@ -126,11 +126,12 @@ command-line option when running LAMMPS to see the offending line.
 
 E: Read data add offset is too big
 
-UNDOCUMENTED
+It cannot be larger than the size of atom IDs, e.g. the maximum 32-bit
+integer.
 
 E: Non-zero read_data shift z value for 2d simulation
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: No bonds allowed with this atom style
 
@@ -159,23 +160,23 @@ run a 2d simulation.
 
 E: Cannot read_data without add keyword after simulation box is defined
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use read_data add before simulation box is defined
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use read_data offset without add flag
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use read_data shift without add flag
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot use read_data extra with add flag
 
-UNDOCUMENTED
+Self-explanatory.
 
 W: Atom style in data file differs from currently defined atom style
 
@@ -471,7 +472,8 @@ outside a non-periodic simulation box.
 
 E: Subsequent read data induced too many bonds per atom
 
-UNDOCUMENTED
+See the create_box extra/bond/per/atom or read_data "extra bond per
+atom" header value to set this limit larger.
 
 E: Bonds assigned incorrectly
 
@@ -480,7 +482,8 @@ This means there is something invalid about the topology definitions.
 
 E: Subsequent read data induced too many angles per atom
 
-UNDOCUMENTED
+See the create_box extra/angle/per/atom or read_data "extra angle per
+atom" header value to set this limit larger.
 
 E: Angles assigned incorrectly
 
@@ -490,7 +493,8 @@ definitions.
 
 E: Subsequent read data induced too many dihedrals per atom
 
-UNDOCUMENTED
+See the create_box extra/dihedral/per/atom or read_data "extra
+dihedral per atom" header value to set this limit larger.
 
 E: Dihedrals assigned incorrectly
 
@@ -500,7 +504,8 @@ definitions.
 
 E: Subsequent read data induced too many impropers per atom
 
-UNDOCUMENTED
+See the create_box extra/improper/per/atom or read_data "extra
+improper per atom" header value to set this limit larger.
 
 E: Impropers assigned incorrectly
 
@@ -510,11 +515,11 @@ definitions.
 
 E: Too few values in body lines in data file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Too many values in body lines in data file
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Too many lines in one body in data file - boost MAXBODY
 
@@ -552,17 +557,4 @@ The specified file cannot be opened.  Check that the path and name are
 correct. If the file is a compressed file, also check that the gzip
 executable can be found and run.
 
-U: Cannot read_data after simulation box is defined
-
-The read_data command cannot be used after a read_data,
-read_restart, or create_box command.
-
-U: Cannot read_data add and merge
-
-These options are not yet supported.
-
-U: Cannot use non-zero z offset in read_data for 2d simulation
-
-The offset option is not yet supported.
-
 */
diff --git a/src/read_restart.h b/src/read_restart.h
index 50bbf34937..0c4661cb55 100644
--- a/src/read_restart.h
+++ b/src/read_restart.h
@@ -174,7 +174,7 @@ Your input script cannot change these restart file settings.
 
 E: Illegal or unset periodicity in restart
 
-UNDOCUMENTED
+This error should not normally occur unless the restart file is invalid.
 
 E: Invalid flag in header section of restart file
 
@@ -222,14 +222,14 @@ contain a recognized byte-orderomg flag at the beginning.
 
 E: Illegal size string or corrupt restart
 
-UNDOCUMENTED
+This error should not normally occur unless the restart file is invalid.
 
 E: Illegal size integer vector read requested
 
-UNDOCUMENTED
+This error should not normally occur unless the restart file is invalid.
 
 E: Illegal size double vector read requested
 
-UNDOCUMENTED
+This error should not normally occur unless the restart file is invalid.
 
 */
diff --git a/src/region.h b/src/region.h
index 0c4fb28a24..d330a9bf3e 100644
--- a/src/region.h
+++ b/src/region.h
@@ -102,7 +102,7 @@ Self-explanatory.
 
 E: Can only use Kokkos supported regions with Kokkos package
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Illegal ... command
 
diff --git a/src/set.h b/src/set.h
index e8149d2f92..1be9faef1c 100644
--- a/src/set.h
+++ b/src/set.h
@@ -100,27 +100,27 @@ Self-explanatory.
 
 E: Cannot set meso/e for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set meso/cv for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set meso/rho for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set smd/mass/density for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set smd/contact/radius for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set dpd/theta for this atom style
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Set command integer vector does not exist
 
@@ -168,7 +168,7 @@ Self-explanatory.
 
 E: Cannot set quaternion with xy components for 2d system
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Cannot set theta for atom that is not a line
 
@@ -211,8 +211,4 @@ E: Variable for set command is invalid style
 
 Only atom-style variables can be used.
 
-U: Cannot set meso_rho for this atom style
-
-Self-explanatory.
-
 */
diff --git a/src/timer.h b/src/timer.h
index 3244267b44..ef5306cb2e 100644
--- a/src/timer.h
+++ b/src/timer.h
@@ -80,6 +80,8 @@ class Timer : protected Pointers {
 
 E: Illegal ... command
 
-UNDOCUMENTED
+Self-explanatory.  Check the input script syntax and compare to the
+documentation for the command.  You can use -echo screen as a
+command-line option when running LAMMPS to see the offending line.
 
 */
diff --git a/src/update.h b/src/update.h
index 3721bfbed4..bbb29bc7ee 100644
--- a/src/update.h
+++ b/src/update.h
@@ -101,8 +101,4 @@ Dynamic regions (see the region command) have a time dependence.
 Thus you cannot change the timestep when one or more of these
 are defined.
 
-U: Too big a timestep
-
-Specified timestep is too large.
-
 */
diff --git a/src/variable.h b/src/variable.h
index 753604e60c..05ea3f57e9 100644
--- a/src/variable.h
+++ b/src/variable.h
@@ -152,7 +152,7 @@ number of processor partitions.
 
 E: Cannot open temporary file for world counter.
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: All universe/uloop variables must have same # of values
 
@@ -418,15 +418,15 @@ Only file-style or atomfile-style variables can be used with next().
 
 E: Invalid is_active() function in variable formula
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid is_available() function in variable formula
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Invalid is_defined() function in variable formula
 
-UNDOCUMENTED
+Self-explanatory.
 
 E: Indexed per-atom vector in variable formula without atom map