I reckon this:
All Posters Forum
sounds better than
All Poster Forum
I am first to admit my English is dire but this sounds wrong in some way to me.
All is plural, so Poster should be plural too?
Yes, I know, there are bigger things to be concerned about like climate change and the price of fish in China.... But for me, now, back to the search for the ultimate poster... :-)
Cheers,
Steve