They're basically like an online fanclub only there's no activities or anything, just a list of names. I like to put the codes in my user info and stuff. The thing that gets me about it though is that making fanlistings is outweighing making shrines because people don't want to put actual work into them. I admit I run two fanlistings myself (for Sylphiel and the V/F relationship) but I made them part of my shrines for them. ^^