Another round of string clarification and adding TRANSLATORS comments.

grub-core/commands/i386/pc/drivemap.c

@@ -36,6 +36,10 @@ static grub_uint32_t *const int13slot = (grub_uint32_t *) (4 * 0x13);
 
 /* Remember to update enum opt_idxs accordingly.  */
 static const struct grub_arg_option options[] = {
+  /* TRANSLATORS: In this file "mapping" refers to a change GRUB makes so if
+     your language doesn't have an equivalent of "mapping" you can
+     use the word like "rerouting".
+   */
   {"list", 'l', 0, N_("Show the current mappings."), 0, 0},
   {"reset", 'r', 0, N_("Reset all mappings to the default values."), 0, 0},
   {"swap", 's', 0, N_("Perform both direct and reverse mappings."), 0, 0},

grub-core/commands/i386/pc/play.c

@@ -183,6 +183,8 @@ grub_cmd_play (grub_command_t cmd __attribute__ ((unused)),
 
   if (argc < 1)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, 
+		       /* TRANSLATORS: it's musical notes, not the notes
+			  you take.  */
 		       N_("filename or tempo and notes expected"));
 
   if (argc == 1)