Oh, you are probably thinking of Roleplays, or RPs. A few of them relate to the warriors book series, but most of them have nothing to do with it. Different RP threads aren't usually related to other threads unless specified. To join an RP, you will first have to look at the very first post on the thread. There, the operator of the RP will specify all rules, condition, etc. They will have a list with the all the characters owned by other members. They will also have a form for you to fill out which you will PM (PrivateMessage) to the operator with the specs on your character/s. Then, you will go out on the thread and you will Role Play your character/s with others' characters. It's kind of like you're the narrator. I'll give an example.
horsecrazychicklovingkid: Keisha froze, not even daring to move. Her eyes scanned the trees ahead of her. She heard something, maybe it was just the wind, but maybe it wasn't. She wasn't taking any chances.
DuckLover2399: A silent shadow watched her from behind. His eyes glinted evilly. "Such a fool" he whispered. He quietly fitted an arrow into the bow at his side. He raised it and prepared to shoot.
EquineHugger3: "Don't shoot!" Lara yelled, swinging down from a branch above him and knocking the bow from his hands.