diff --git a/conf/type/__cron/man.text b/conf/type/__cron/man.text
index 039be04c..47f47456 100644
--- a/conf/type/__cron/man.text
+++ b/conf/type/__cron/man.text
@@ -39,6 +39,8 @@ raw::
    Take whatever the user has given instead of time and date fields.
    If given, all other time and date fields are ignored.
    Can for example be used to specify cron EXTENSIONS like reboot, yearly etc.
+   See crontab(5) for the extensions if any that your cron implementation
+   implements.
 
 
 EXAMPLES