Um...

[Cariad]

I've been seeing loads of people with sigs that have a section called "PokeCommunity Family" and then they list other members. *Wow, I sound like a dweeb*

What exactly is this all about?

 

[Hybrid Trainer]

PC families are kind of like unofficial pairs. You meet someone and you become friends with them, so to show your friendship you put each other in your signatures and say that their your mother/sister/uncle/whatever.