Document Type Code (DOC)

Code	Type
1	Visa
2	Passport
3	Military identification
4	Drivers license
5	National identity document
6	Vaccination certificate
7	Alien registration number
8	Insurance policy number
9	Tax exemption number
10	Vehicle registration/license number
11	Border crossing card
12	Refugee travel document
13	Pilot's license
14	Permanent resident card
15	Redress number
16	Known traveler number
17	Non-standard
18	Merchant mariner
19	Air Nexus card
20	Crew member certificate
21	Passport card
22	Naturalization certificate