Forum:What is a nosubst template?

What is a nosubst template? I want to know because I was asking my friend how to make it so when you edit a page with my signature on it in source mode my signature shows up as instead of all my signature code, and he said to use a nosubst template. May StarClan light your path,  Random  Kitten   22:19, July 31, 2012 (UTC)