Bulletin boards are often made of a material such as cork to facilitate addition and removal of messages, as well as a writing surface such as blackboard or whiteboard.
Bulletin boards can also be entirely in the digital domain and placed on computer networks so people can leave and erase messages for other people to read and see, as in a bulletin board system.
Dormitory corridors, well-trafficked hallways, lobbies, and freestanding kiosks often have cork boards attached to facilitate the posting of notices.
At some universities, lampposts, bollards, trees, and walls often become impromptu posting sites in areas where official boards are sparse in number.
Internet forums are a replacement for traditional bulletin boards.