An extension of the ITU-TV.42 standard modemprotocol to included compression using a Lempel-Ziv related technique, which detects frequently occurring character strings and replaces them with tokens. This is similar to the Unixcompress utility. Typical compression for text is 50% or better with nearly 20% gain from synchronous conversion this gives reduces transmission time by almost 60%. [Details? On-line spec?] (2004-08-02)