Index: src/conf_core.h
===================================================================
--- src/conf_core.h	(revision 20837)
+++ src/conf_core.h	(revision 20838)
@@ -102,7 +102,7 @@
 
 		CFT_STRING emergency_name;         /* file name template for emergency save anonymous .pcb files (when pcb-rnd crashes); optional field: %ld --> pid; must be shorter than 240 characters. Don't do emergency save if this item is empty. */
 		CFT_STRING emergency_format;       /* if set, use this format for the backups; if unset, use the default format */
-		CFT_STRING backup_name;            /* file name template for periodic backup anonymous .pcb files; optional fields: %P --> pid */
+		CFT_STRING backup_name;            /* file name template for periodic backup of board files; optional fields (the usual % substitutions work) */
 		CFT_STRING backup_format;          /* if set, use this format for the backups; if unset or set to 'original', use the original format */
 
 		CFT_STRING save_command;           /* command to pipe the pcb, footprint or buffer file into, when saving (makes lihata persist impossible) */
Index: src/plug_io.c
===================================================================
--- src/plug_io.c	(revision 20837)
+++ src/plug_io.c	(revision 20838)
@@ -888,11 +888,8 @@
 		backup_timer = pcb_gui->add_timer(backup_cb, 1000 * conf_core.rc.backup_interval, x);
 }
 
-/* ---------------------------------------------------------------------------
- * creates backup file.  The default is to use the pcb file name with
- * a "-" appended (like "foo.pcb-") and if we don't have a pcb file name
- * then use the template in conf_core.rc.backup_name
- */
+/* Saves the board in a backup file using the name configured in
+   conf_core.rc.backup_name */
 void pcb_backup(void)
 {
 	char *filename = NULL;
@@ -899,7 +896,6 @@
 	const char *fmt = NULL;
 	pcb_plug_io_t *orig;
 
-	/* conf_core.rc.backup_name has %.8i which will be replaced by the process ID */
 	filename = pcb_build_fn(conf_core.rc.backup_name);
 	if (filename == NULL) {
 		fprintf(stderr, "pcb_backup(): can't build file name for a backup\n");