diff --git a/src/deprecated.cpp b/src/deprecated.cpp
new file mode 100644
index 0000000000..ed9a9e6de4
--- /dev/null
+++ b/src/deprecated.cpp
@@ -0,0 +1,48 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing authors:  Axel Kohlmeyer (Temple U),
+------------------------------------------------------------------------- */
+
+#include <cstring>
+#include "deprecated.h"
+#include "comm.h"
+#include "force.h"
+#include "error.h"
+#include "input.h"
+
+using namespace LAMMPS_NS;
+
+static void writemsg(LAMMPS *lmp, const char *msg, int abend=1)
+{
+  if (lmp->comm->me == 0) {
+    if (lmp->screen) fputs(msg,lmp->screen);
+    if (lmp->logfile) fputs(msg,lmp->logfile);
+  }
+  if (abend)
+    lmp->error->all(FLERR,"This command is no longer available");
+}
+
+/* ---------------------------------------------------------------------- */
+
+void Deprecated::command(int narg, char **arg)
+{
+  if (strcmp(input->command,"deprecated") == 0) {
+    writemsg(lmp,"\nCommand 'deprecated' is a dummy command\n\n",0);
+
+  } else if (strcmp(input->command,"XXX") == 0) {
+    writemsg(lmp, "\nCommand 'XXX' has been removed from LAMMPS "
+             "after the\n## XXX 20## stable release.\n\n");
+  }
+}
diff --git a/src/deprecated.h b/src/deprecated.h
new file mode 100644
index 0000000000..9835579245
--- /dev/null
+++ b/src/deprecated.h
@@ -0,0 +1,70 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifdef COMMAND_CLASS
+
+CommandStyle(deprecated,Deprecated)
+CommandStyle(XXX,Deprecated)
+
+#else
+
+#ifndef LMP_DEPRECATED_H
+#define LMP_DEPRECATED_H
+
+#include "pointers.h"
+
+namespace LAMMPS_NS {
+
+class Deprecated : protected Pointers {
+ public:
+  Deprecated(class LAMMPS *lmp) : Pointers(lmp) {};
+  void command(int, char **);
+};
+
+}
+
+#endif
+#endif
+
+/* ERROR/WARNING messages:
+
+W: Ignoring unknown or incorrect info command flag
+
+Self-explanatory.  An unknown argument was given to the info command.
+Compare your input with the documentation.
+
+E: Unknown name for info package category
+
+Self-explanatory.
+
+E: Unknown name for info newton category
+
+Self-explanatory.
+
+E: Unknown name for info pair category
+
+Self-explanatory.
+
+E: Unknown category for info is_active()
+
+Self-explanatory.
+
+E: Unknown category for info is_available()
+
+Self-explanatory.
+
+E: Unknown category for info is_defined()
+
+Self-explanatory.
+
+*/
diff --git a/src/input.h b/src/input.h
index 80b3e8c7da..be320a41ec 100644
--- a/src/input.h
+++ b/src/input.h
@@ -24,6 +24,8 @@ namespace LAMMPS_NS {
 class Input : protected Pointers {
   friend class Info;
   friend class Error;
+  friend class Deprecated;
+
  public:
   int narg;                    // # of command args
   char **arg;                  // parsed args for command
@@ -38,9 +40,11 @@ class Input : protected Pointers {
                                  // substitute for variables in a string
   int expand_args(int, char **, int, char **&);  // expand args due to wildcard
 
+ protected:
+  char *command;               // ptr to current command
+
  private:
   int me;                      // proc ID
-  char *command;               // ptr to current command
   int maxarg;                  // max # of args in arg
   char *line,*copy,*work;      // input line & copy and work string
   int maxline,maxcopy,maxwork; // max lengths of char strings
diff --git a/src/pair_deprecated.cpp b/src/pair_deprecated.cpp
index 9045b3f2a8..143cfd46f4 100644
--- a/src/pair_deprecated.cpp
+++ b/src/pair_deprecated.cpp
@@ -15,6 +15,7 @@
    Contributing author: Axel Kohlmeyer (Temple U)
 ------------------------------------------------------------------------- */
 
+#include <cstring>
 #include "pair_deprecated.h"
 #include "pair_hybrid.h"
 #include "comm.h"