Originally Posted by ishi

.....III) A user may have more than one thread open if each thread serves a different purpose. Note that having multiple threads with the same purpose may result in infractions.

Purposes:
.....[A] : Auction : For auctioning off art/items.
.....[B] : Buying : For requesting art/items.
.....[S] : Selling : For selling art/items.
.....[T] : Trading : For swapping items.
.....[R] : Request : For requesting art