AVATAR
From Just Solve the File Format Problem
AVATAR (Advanced Video Attribute Terminal Assembler and Recreator) is a set of control codes for specifying such things as color changes, part-screen scrolling, and pattern compression in text to be displayed on a terminal, similar in concept to the ANSI codes, but somewhat more compact. They were introduced in the Opus-CBCS bulletin board system software (as a subset of its Opus Embedded Commands), and later standardized in FidoNet protocol documents. This system got some use in BBSs, but didn't reach the degree of popularity of ANSI.
Files sometimes were stored with .avt extensions, but could be found in other extensions (including .bbs) when used in conjunction with a BBS.
