diff --git a/man5/locale.5 b/man5/locale.5
index b374b8f77..54f47ff60 100644
--- a/man5/locale.5
+++ b/man5/locale.5
@@ -777,7 +777,10 @@ The definition starts with the string
 .B LC_NAME
 in the first column.
 
-The following keywords are allowed:
+The following keywords are allowed but only
+.IR name_fmt
+should be always defined, others only if there is common convention to
+use them in the language in question:
 .TP
 .I name_fmt
 followed by a string containing field descriptors that define
@@ -982,7 +985,8 @@ The appropriate representation of the
 .B am
 and
 .B pm
-strings.
+strings. This should not be defined for locales not using AM/PM
+convention.
 .TP
 .I d_t_fmt
 The appropriate date and time format.