Affix file . AGEMA file. Mozilla Firefox dictionary file
AFF file suffix is associated with Acorn/Risc OS graphic application Draw. File contains draw similar to Windows WMF and SVG vector-based format. Extensions used to map this file come in two varieties. The first is a word describing the file - in this case ".draw" which is ".drw" in the 8.3 parlance. The second way of mapping the file is to use a literal form of the RISC OS filetype system. In this, three bytes provide a range of possible file types from &000 to &FFF (there are no extensions, just "type" metadata). In this case, Acorn DrawFiles would be given the extension ".aff" because the file is type &AFF, or 0xAFF, $HAFF.
File extension AFF is related to AnyForm application.
Disk image created in the Advanced Forensics Format (AFF), an open file format used to capture digital evidence for legal proceedings; can store both raw disk data and arbitrary metadata; supports two kinds of compression, zlib and LZMA. An AFF file can be divided into a split archive of multiple files that use the .AFD file extension. Advanced Forensics Format programs can also extract metadata from the disk image and store it separately in an .AFM file.
The AFF file extension was also reported to have been used in Nvu text editor. Probably some data file.