bulletin board

noun2

1. •
   A board on which messages may be posted, especially one in a public space.

   • Somewhere near Fillmore she found the symbol tacked to the bulletin board of a laundromat, among other scraps of paper offering cheap ironing and baby sitters. — 1966
2. •
   Ellipsis of bulletin board system.

   • Some bulletin board subscribers can now dial up displays for their IBM PC or PC XT in living color—and see the results in less than a second. — 1984