diff --git a/doc/atom_modify.html b/doc/atom_modify.html
index de192c7067..a4cad5b9f1 100644
--- a/doc/atom_modify.html
+++ b/doc/atom_modify.html
@@ -61,12 +61,13 @@ commands are two examples of commands that require this setting to
 work efficiently.  Several <A HREF = "fix.html">fixes</A>, most notably time
 integration fixes like <A HREF = "fix_nve.html">fix nve</A>, also take advantage of
 this setting if the group they operate on is the group specified by
-this command.
+this command.  Note that specifying "all" as the group-ID effectively
+turns off the <I>first</I> option.
 </P>
 <P>It is OK to use the <I>first</I> keyword with a group that has not yet been
-defined, e.g. to use the atom_modify command at the beginning of your
-input script.  LAMMPS will check that the group exists before the
-first simulation is performed.
+defined, e.g. to use the atom_modify first command at the beginning of
+your input script.  LAMMPS does not use the group until a simullation
+is run.
 </P>
 <P>The <I>sort</I> keyword turns on a spatial sorting or reordering of atoms
 within each processor's sub-domain every <I>Nfreq</I> timesteps.  This can
@@ -113,7 +114,7 @@ command.
 </P>
 <P>The <I>first</I> and <I>sort</I> options cannot be used together.  Since sorting
 is on by default, it will be turned off if the <I>first</I> keyword is
-used.
+used with a group-ID that is not "all".
 </P>
 <P><B>Related commands:</B> none
 </P>
diff --git a/doc/atom_modify.txt b/doc/atom_modify.txt
index 2a2b3bf15e..e7a0afd8ca 100644
--- a/doc/atom_modify.txt
+++ b/doc/atom_modify.txt
@@ -55,12 +55,13 @@ commands are two examples of commands that require this setting to
 work efficiently.  Several "fixes"_fix.html, most notably time
 integration fixes like "fix nve"_fix_nve.html, also take advantage of
 this setting if the group they operate on is the group specified by
-this command.
+this command.  Note that specifying "all" as the group-ID effectively
+turns off the {first} option.
 
 It is OK to use the {first} keyword with a group that has not yet been
-defined, e.g. to use the atom_modify command at the beginning of your
-input script.  LAMMPS will check that the group exists before the
-first simulation is performed.
+defined, e.g. to use the atom_modify first command at the beginning of
+your input script.  LAMMPS does not use the group until a simullation
+is run.
 
 The {sort} keyword turns on a spatial sorting or reordering of atoms
 within each processor's sub-domain every {Nfreq} timesteps.  This can
@@ -107,7 +108,7 @@ command.
 
 The {first} and {sort} options cannot be used together.  Since sorting
 is on by default, it will be turned off if the {first} keyword is
-used.
+used with a group-ID that is not "all".
 
 [Related commands:] none
 
diff --git a/doc/communicate.html b/doc/communicate.html
index 3d691b24f5..8eeb707ebf 100644
--- a/doc/communicate.html
+++ b/doc/communicate.html
@@ -31,8 +31,8 @@
 </P>
 <PRE>communicate multi
 communicate multi group solvent
-communicate single ghost yes
-communicate single cutoff 5.0 ghost yes 
+communicate single vel yes
+communicate single cutoff 5.0 vel yes 
 </PRE>
 <P><B>Description:</B>
 </P>
diff --git a/doc/communicate.txt b/doc/communicate.txt
index 51169fe99d..b24ff976f3 100644
--- a/doc/communicate.txt
+++ b/doc/communicate.txt
@@ -24,8 +24,8 @@ keyword = {cutoff} or {group} or {vel} :l
 
 communicate multi
 communicate multi group solvent
-communicate single ghost yes
-communicate single cutoff 5.0 ghost yes :pre
+communicate single vel yes
+communicate single cutoff 5.0 vel yes :pre
 
 [Description:]