BBCode

BBCode or Bulletin Board Code is a lightweight markup language used to format posts in many message boards. The available tags are usually indicated by square brackets surrounding a keyword, and they are parsed by the message board system before being translated into a markup language that web browsers understand—usually HTML or XHTML.

BBCode was first introduced in 1998 by the messageboard software Ultimate Bulletin Board (UBB). This is why BBCode is sometimes referred to as UBBCode.