This paper aims at describing the use of language on theinternet, especially language terms in chatting. It is claimedthat the language terms have an important role for thechatters to make interaction and relationship with eachother for certain purposes. The important role of languagecan be seen from the fact that many chatters use differentlanguage styles and speech variations in chatting over theInternet Relay Chat (IRC). The model of IRCcommunication is a kind of communication media forcommunication (chatting) by using computer keyboard inwriting symbols or "emoticons", and codes (register) in theconversation with other chatters. The writer usesdescriptive method combined with socio-pragmaticsapproach of Grice’s Maxim theories to explain the specialterms of language use in chatting. The study was based onthe data from 13 speech channels and 10 couples of privatespeech on mIRC program and YM in Yogyakarta area.Based on the elaboration, the writer has found four criteriaof chatting conversation as follows. (1) Chatting has aspecial term in the use of codes (register) for conveyingsomething to their partners in speaking, such asabbreviations. (2) Chatting has special forms of Emoticon.(3) Chatting has special identity codes and (4) Chatting hasspecial lengthened the words.