Message boards were invented by nerdy types, and have their own language

Board: an area of the message boards eg ‘UK CAB’, ‘News, events, announcements’.  Boards can be public or member-only.

Subject: a discussion on a subject – sometimes called a topic or thread.

Post: a message in a subject.

Personal message: a private member-to-member message – sometimes called a PM (these are truly private and cannot be seen by moderators or administrators).

Moderator: member enlisted to manage a one or more boards on the message boards.

Administrator: member with overall administrative control of the message boards, including maintenance of the database and software.

Sticky subject: subject pinned to the top of a board to make sure it is visible.

Locked subject: subject which is not open for posting.

Spam: rubbish posts.

Off-topic: unconnected to the subject of a board or topic (example: a post about Britney Spear’s mental health in a discussion on the CNS side effects of efavirenz).

Troll: trouble-maker, typically someone who joins a forum with the express purpose of upsetting people. Hence trolling (deliberately causing trouble).

Flame: nasty personal attack. Hence flamer (rude person), flaming (insulting someone online) and flame-bait (a post – innocent or otherwise – likely to elicit a very personal, insulting response).

Hijack: steer a thread off-topic by introducing and discussing an entirely unrelated subject.

Cross-post: post the same message on a message board in several places, or post the same message on several different message boards.

BBC: bulletin board code, a set of tags to pretty up your message, add bold etc.