Unique "3-letter" country codes published in ISO 3166-1 alpha-3 codes' list to be used within the NATO Codification System (NCS) to distinguish geographical entities, nations and countries, whenever necessary. Country codes present in ISO 3166-1 but not listed in this table are valid country codes and must be accepted.

3 letter Country Code (CTR) codes are also used as:

• NATO REFERENCE NUMBER ACTION ACTIVITY CODES (DRN 8750)
• DESTINATION CODE (DRN 8710)
• SOURCE CODE (DRN 8709)
• COUNTRY CODE (DRN 3408)

Luxembourg: all transactions are catalogued by Belgium (NCB Code 13)

Iceland: NSNs are allocated by the 1st NATO or sponsored Tier2 nation which uses the item of supply.

NCAGE Code structure explanation:
# = numeral
* = alpha/numerical

Canada will progressively replace existing NCAGE Codes with prefix "L" as file maintenance action occurs. Canadian NCAGE Codes with structure #***# created prior to 2002 and identified by US F/DDC (DRN 4235) value 3 continue to be valid (see ACodP-1, Chapter IV, Annex G16 - Table 25).

Luxembourg: all NCAGEs are allocated by Belgium (NCAGE structure B***#)

Iceland: all NCAGEs are allocated by NSPA (NCAGE structure S***#)

Non-NATO/Non Tier2 sponsored nations: All NCAGEs of these nations exchanged at the international level are assigned by NSPA (NCAGE structure S***#). These nations can also assign and use national format CAGE codes. These national CAGE codes are used for national purpose only and cannot be exchanged at international level except within the framework of a bilateral agreement established between two countries.

NATO & International entities: all NCAGEs are allocated by NSPA (NCAGE structure I***#)

NOTE:The letter "I" must be used only in the first position of International NCAGEs assigned by NSPA. The letter "O" must not be used in NCAGEs.