Required field.

3-letter ISO country codes, lower-case, reflecting the place(s) of publication recorded in 260 $a.

See CODES for UNBIS country codes in field 049.

If more than one place of publication is recorded in 260 $a subfields, then the country codes are recorded in 049 in a continuous string, in the same order in which they are recorded in 260 $a.
The first country code recorded in 049 should be the same as that recorded in 008/15-17.
Additional 049 country codes are added for other places of publication identified in field 500 notes.

Examples:

049 $a che
260 $a Geneva
008/15-17 che

049 $a usache
260 $a New York ; $a Geneva
008/15-17 usa

049 $a gbrkenjpn
260 $a London ; $a Nairobi
008/15-17 gbr
500 $a Japanese ed. published: Tokyo : Haro Shobo, 2000