ADI-var
Aerospace and Defence Identifier (variable length)
urn:epc:id:adiWhat is ADI-var?
US Department of Defence and aerospace identifier. Uses a CAGE code (Commercial and Government Entity) or DoDAAC (DoD Activity Address Code) instead of a GS1 Company Prefix. Fields are 6-bit encoded and null-terminated, making this a variable-length encoding.
Used for: Military parts, aerospace components, US DoD supply chain items tagged per MIL-STD-129 and ATA Spec 2000.
Field layout
The first 8 bits are always the header (0x3B = 59 decimal), which identifies this as ADI-var.
Defined in GS1 EPC Tag Data Standard v2.3, Section 14.6.14.1 (Aerospace and Defence Identifier), encoding procedure in Section 14.6.14.1.
| Bits | Field | Description |
|---|---|---|
0–7 | Header | 0x3B (59) - identifies this encoding as ADI-var |
8–10 | Filter | Filter value for aerospace/defence items. |
11–46 | CAGE/DoDAAC | 6 characters, 36 bits. A 5-character CAGE code (padded) or 6-character DoDAAC identifying the organisation. |
47–52 | Part Number | 6-bit encoded, null-terminated. Variable-length alphanumeric part number. |
53–58 | Serial Number | 6-bit encoded, null-terminated. Variable-length alphanumeric serial number. |
Filter values
The 3-bit filter field does not affect identity - it tells readers what packaging level or category the tag is applied to. The same item with different filter values has the same Pure Identity URI.
Source: GS1 EPC TDS v2.3, Table 10-11.
| Value | Name | Description |
|---|---|---|
0 | All others | Unspecified aerospace/defence item |
1 | Reserved | Not yet assigned |
2 | Reserved | Not yet assigned |
3 | Reserved | Not yet assigned |
4 | Reserved | Not yet assigned |
5 | Reserved | Not yet assigned |
6 | Reserved | Not yet assigned |
7 | Reserved | Not yet assigned |
Source
GS1 EPC Tag Data Standard, Release 2.3, Ratified October 2025 - see Section 14.6.14.1 (Aerospace and Defence Identifier) and Section 14.6.14.1 for the encoding procedure. Read the EPC encoding guide for a full worked example of decoding hex to URI.