In the Silicon Valley / San Jose / Bay area, there was a BBS that had a hierarchical message board, Replies were ordered under posts or other replies. In the 80’s this was an unusual feature of a bulletin system. The BBS was named for a character from some story. It was a hard to pronounce word/name starting with the letter ‘P’, and we mostly referred to the BBS as ‘Pretzel’ as that was a close approximation to the original word. Anyone know which BBS I am talking about?