diff --git a/include/file.h b/include/file.h
index 98494cb0..daeae24b 100644
--- a/include/file.h
+++ b/include/file.h
@@ -86,9 +86,11 @@ struct empfile {
 #define EFF_MEM		bit(8)
 /* Table is read-only */
 #define EFF_RDONLY	bit(9)
+/* Table is customized (configuration tables only) */
+#define EFF_CUSTOM	bit(10)
 /* Transient flags, only occur in argument of ef_open() */
 /* Create table file, clobbering any existing file */
-#define EFF_CREATE	bit(10)
+#define EFF_CREATE	bit(11)
 
 /*
  * Empire `file types'
diff --git a/src/lib/commands/vers.c b/src/lib/commands/vers.c
index 98411c6c..5fd1ff1f 100644
--- a/src/lib/commands/vers.c
+++ b/src/lib/commands/vers.c
@@ -47,6 +47,7 @@
 #include "commands.h"
 #include "file.h"
 
+static void show_custom(void);
 static void show_opts(int val);
 
 int
@@ -209,6 +210,7 @@ vers(void)
     pr("\n");
     pr("You can have at most %d BTUs.\n", max_btus);
     pr("You are disconnected after %d minutes of idle time.\n", max_idle);
+    show_custom();
     pr("\nOptions enabled in this game:\n        ");
     show_opts(1);
     pr("\n\nOptions disabled in this game:\n        ");
@@ -223,6 +225,22 @@ vers(void)
     return RET_OK;
 }
 
+static void
+show_custom(void)
+{
+    char *sep = "\nCustom characteristics in this game:\n        ";
+    int i;
+
+    /* TODO wrap long lines */
+    for (i = 0; i < EF_MAX; i++) {
+	if (ef_flags(i) & EFF_CUSTOM) {
+	    pr("%s%s", sep, ef_nameof(i));
+	    sep = ", ";
+	}
+    }
+    if (*sep == ',')
+	pr("\n");
+}
 
 static void
 show_opts(int val)
diff --git a/src/lib/common/conftab.c b/src/lib/common/conftab.c
index c9f9216d..2389645f 100644
--- a/src/lib/common/conftab.c
+++ b/src/lib/common/conftab.c
@@ -109,7 +109,8 @@ read_config_table_file(char *fname)
 	return -1;
     }
 
-    for (n = 0; (res = xundump(fp, fname, EF_BAD)) >= 0; n++) ;
+    for (n = 0; (res = xundump(fp, fname, EF_BAD)) >= 0; n++)
+	empfile[res].flags |= EFF_CUSTOM;
     if (res != EF_BAD && n == 0)
 	fprintf(stderr, "Warning: configuration file %s is empty\n", fname);