Recommendation T.6 defines the facsimile coding schemes and their control functions to be used in the Group 4 facsimile.This Recommendation should be read in conjunction with the following Recommendations:T.503 A document application profile for the interchange of Group 4 facsimile documents T.521 Communication application profile for document bulk transfer based on the session service(according to the rules defined in T.62 bis) T.563 Terminal characteristics for Group 4 facsimile apparatus T.73 Document interchange protocol for the Telematic services T.62 Control procedures for Teletex and Group 4 facsimile services T.62bis Control procedures for Teletex and Group 4 facsimile services based on Recommendations X.215/X.225 T.70 Network-independent basic transport service for Telematic services F.161 International Group 4 facsimile service In addition, in the case of Group 4 Class II/III (Teletex or mixed mode of operation), the following Recommendations should also be read:T.60 Terminal equipment for use in the Teletex service T.61 Character repertoire and coded character sets for the international Teletex service T.72 Terminal capabilities for mixed mode of operation.