mug file vs mug book

mug file and mug book both are nouns.

Word	Noun	Adjective	Verb	Adverb
mug file	Yes	No	No	No
mug book	Yes	No	No	No

As nouns, mug file and mug book are synonyms defined as:

mug file and mug book: a file of mug shots (pictures of criminals that are kept on file by the police)

mug file (noun)	mug book (noun)
a file of mug shots (pictures of criminals that are kept on file by the police)	a file of mug shots (pictures of criminals that are kept on file by the police)