what count's as RP?

so when going to make a group I noticed a rule about Role Playing, when I went to the post about it knighty didn't give any definition or examples, so I'm somewhat worried, I want to make a group to replace the displaced group, but crossover's require some level of RP, what do you guys think? would making a group like that be band? I mean we wouldn't have RP in the comments or forums or anything, but crossovers would require a level of it.