本标准规定了使用CCITT建议T.4和T.6（第3组）以及位图图像（无压缩）编码的双层电子图像交换的文件格式。本标准旨在将mat的一个独立文件纳入一个标准，用于在传真以外的环境中进行双层图像文件传输。

This standard specifies a file format for the exchange of bi-level electronic images coded using CCITT Recommendations T.4 and T.6, (Group 3) plus bit-mapped images (having no compression). This standard aims to put into one standard, a self-contained file for-mat for bi-level image file transfer in environments other than facsimile.