Group 4 Facsimile: The mode of black and white facsimile operation defined in ITU-T Recommendation T.563 and CCITT Recommendation T.6. Note 1: Group 4 Facsimile uses bandwidth compression techniques to transmit, essentially without errors, a 216 ª 279-mm document, i.e. , an 8½ ª 11-inch document, at a nominal resolution of 8 lines/mm in less than 1 minute over a public data network voice-grade circuit . Note 2: When any CCITT or CCIR Recommendation is modified by the ITU-T, the modified document is designated as an ITU-T Recommendation.
Type I Facsimile: The mode of digital black and white facsimile operation defined in MIL-STD-188-161 used for transmission of bi-level information ( e.g. , text and simple graphics ). Note: Type I facsimile is interoperable with the black-and-white facsimile mode of STANAG 5000 and is designed for operation over noisy communications links such as tactical channels.
Type II Facsimile: The mode of gray-scale facsimile operation defined in MIL-STD-188-161 used for transmission of multi-level information ( e.g. , photographs). Note: Type II facsimile is interoperable with the black-and-white facsimile mode of Type I or STANAG 5000 equipment and is designed for operation over noisy communications links such as tactical channels.