Added cautionary comments

src/fix_move.cpp

@@ -1193,6 +1193,7 @@ int FixMove::pack_restart(int i, double *buf)
     buf[n++] = qoriginal[i][2];
     buf[n++] = qoriginal[i][3];
   }
+  // pack buf[0] this way b/c other fixes unpack it
   buf[0] = n;
   return n;
 }
@@ -1206,6 +1207,7 @@ void FixMove::unpack_restart(int nlocal, int nth)
   double **extra = atom->extra;
 
   // skip to Nth set of extra values
+  // unpack the Nth first values this way b/c other fixes pack them
 
   int m = 0;
   for (int i = 0; i < nth; i++) m += static_cast<int> (extra[nlocal][m]);