We learnt from Ward in a private conversation, that the first **PLoP** asked for submissions that had not yet been published. Nowadays that might be almost impossible. This had more to do with the ACM than with the expectations of the initiators.
That was in 1994. ACM wanted to own the copyright which was hard to claim if a work had been published elsewhere as a book or in another journal.
L and o joined into a ligature
Ward created the name PLoP and insisted that L and o be assembled as a ligature.
They were pioneering in that they assigned Shepherds to authors and asked for work in progress.
There was an official publication later but that was after "workshopping" at the event. "This was as far as we dared break from academic convention." (Ward)
A Pattern Language for Shepherds and Sheep