diff --git a/reference/datetime/functions/strftime.xml b/reference/datetime/functions/strftime.xml
index 4d5e4e6035..ed2ef01a8d 100644
--- a/reference/datetime/functions/strftime.xml
+++ b/reference/datetime/functions/strftime.xml
@@ -628,7 +628,7 @@ Unknown format : 'f'
 Unknown format : 'g'                       ( Two digit representation of the year going by ISO-8601:1988 standards (see %V) )
 Unknown format : 'h'                       ( Abbreviated month name, based on the locale (an alias of %b) )
 Unknown format : 'i'
-Unknown format : 'k'
+Unknown format : 'k'                       ( Hour in 24-hour format, with a space preceding single digits )
 Unknown format : 'l'                       ( Hour in 12-hour format, with a space preceding single digits )
 Unknown format : 'n'                       ( A newline character ("\n") )
 Unknown format : 'o'