File formats naming:
"MP4" files use the Iso Base Media File Format (also "Atom/Box"), originating from QuickTime.
"JPG" files are using the "JFIF" format (=JPEG File interchange format).
"MP3" files are using a ID3 header followed by "Layer 3" (original name) streams dumps.
Older MS Office "DocFile" "OLE" files are using the CFBF "Compound File Binary Format".
Flash: SWF = "Shockwave Flash" first, then "Small Web File".
What's the original name of the "DOS MZ executable" format?
Anything else?
@robryk GZip could use another algorithm (dedicated compression method byte), Gzip files can be made of several members concatenated (see BGZip). Even Zlib uses Deflate in its own way ;)
https://speakerdeck.com/ange/gzip-equals-zip-equals-zlib-equals-deflate?slide=19