file/magic/Magdir/marc21

#--------------------------------------------
# marc21: file(1) magic for MARC 21 Format
#
# Kevin Ford (kefo@loc.gov)
#
# MARC21 formats are for the representation and communication
# of bibliographic and related information in machine-readable
# form.  For more info, see https://www.loc.gov/marc/


# leader position 20-21 must be 45
# and 22-23 also 00 so far, but we check that later.
20	string		45
>0	search/2048	\x1e

# leader starts with 5 digits, followed by codes specific to MARC format
>>0	regex/1l	(^[0-9]{5})[acdnp][^bhlnqsu-z]	MARC21 Bibliographic
!:mime	application/marc
>>0	regex/1l	(^[0-9]{5})[acdnosx][z]	MARC21 Authority
!:mime	application/marc
>>0	regex/1l	(^[0-9]{5})[cdn][uvxy]	MARC21 Holdings
!:mime	application/marc
>>0	regex/1l	(^[0-9]{5})[acdn][w]	MARC21 Classification
!:mime	application/marc
>>0	regex/1l	(^[0-9]{5})[cdn][q]	MARC21 Community
!:mime	application/marc

# leader position 22-23, should be "00" but is it?
>>0	regex/1l	(^.{21})([^0]{2})	(non-conforming)
!:mime	application/marc