The man page states which option is possible for which command name.
** Changed in: bsdmainutils (Ubuntu)
Status: New => Invalid
--
cal man page suggest arguments that don't work
https://bugs.launchpad.net/bugs/413215
You received this bug notification because you are a member of Ubuntu
B
Ok, I've looked at the source code, and apparently that was the expected
behavior of the application. When called cal certain arguments are
allowed, when called ncal other arguments are allowed.
So I've altered the man page to reflect this, and have attached the
patch file. Hope it's helpful.
*