At my old university, passwords could not contain any word in any of its huge database of languages, even if that word was made using substitutions like @ for a.
The trouble with systems like this is that passwords today aren't cracked by humans, but by machines. The key to a password is to make it long--the more the characters, the more time it would take to crack. But long passwords can be tricky to memorise, unless you make it something easy for you to remember. Unfortunately, most of the systems that have you set passwords run on obsolete principles, they want you to make a password that's not only shorter, but hard to remember, when long but easy to remember would be much harder to decrypt. I think some of these folks watched "War Games" once too often....