A bulletin board (pinboard, pin board, noticeboard, or notice board in British English) is a surface designed for posting public messages, such as advertisements for items wanted or for sale, announcements of events, or information. Bulletin boards are frequently made of cork to facilitate message addition and removal, as well as a writing surface such as a blackboard or whiteboard. A combination bulletin board is one that combines a pinboard (corkboard) and a writing surface. Bulletin boards can also be entirely digital and placed on computer networks, allowing people to leave and erase messages for other individuals to view and see, as in a bulletin board system.
University bulletin boards are especially common. They are used by many sports and extracurricular organizations, as well as by everything from local shops to official notices. Cork boards are commonly attached to dorm corridors, heavily trafficked hallways, lobbies, and freestanding kiosks to facilitate the posting of notices. In areas where official boards are scarce, lampposts, bollards, trees, and walls at some universities frequently become impromptu posting sites.