diff --git a/man5/locale.5 b/man5/locale.5
index 6fee9d7dd..c98332221 100644
--- a/man5/locale.5
+++ b/man5/locale.5
@@ -435,6 +435,11 @@ letters.
 If the keyword tolower is not present, the reverse of the
 toupper list is used.
 .TP
+.I map "totitle"
+followed by a list of mapping pairs of
+characters and letters
+to be used in titles (headings).
+.TP
 .I charclass
 followed by a list of locale-specific character class names
 which are then to be defined in the locale.