RG file extension is for 1bit B&W 4bit CMYK Raster Graphics format
Similar to RG
8SVX - Amiga 8-bit Sound format8U - Roman 8 extended character set printer font PageMaker
91 - 91x91 dpi display font Ventura Publisher
96 - 96x96 dpi display font Ventura Publisher
@@@ - Screen files used in installation or instructions
A.D. /B.C. - Macintosh Assembly Source Code
A00 - Archive Section of a file distributed by archives
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