GRAI-170
Global Returnable Asset Identifier (170-bit)
urn:epc:id:graiWhat is GRAI-170?
Same as GRAI-96 but with a 112-bit serial field supporting alphanumeric serials (6-bit encoded).
Used for: Returnable assets requiring alphanumeric serial numbers.
Field layout
The first 8 bits are always the header (0x37 = 55 decimal), which identifies this as GRAI-170. The partition field determines how bits are divided between the company prefix and the following reference field - see the partition table below.
Defined in GS1 EPC Tag Data Standard v2.3, Section 7.6 (Global Returnable Asset Identifier), encoding procedure in Section 14.6.4.
| Bits | Field | Description |
|---|---|---|
0–7 | Header | 0x37 (55) - identifies this encoding as GRAI-170 |
8–10 | Filter | Same filter table as GRAI-96. |
11–13 | Partition | Same partition table as GRAI-96. |
14–53 | Company Prefix | GS1 Company Prefix of the asset owner. |
54–57 | Asset Type | Identifies the type of asset. Size varies by partition. |
58–169 | Serial Number | 112 bits, 6-bit encoded. Supports alphanumeric serial numbers. |
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 10-4.
| Value | Name | Description |
|---|---|---|
0 | All others | Unspecified returnable asset |
1 | Rail vehicle | Tagged rail freight car or locomotive |
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 |
Partition table
The 3-bit partition value determines how the fixed bit space is divided between the company prefix and the following reference field. GS1 company prefixes vary in length (6–12 digits), so the partition tells the decoder where one field ends and the next begins.
Source: GS1 EPC TDS v2.3, Table 14-19.
| Partition | Prefix bits | Prefix digits | Ref bits | Ref digits |
|---|---|---|---|---|
0 | 40 | 12 | 4 | 0 |
1 | 37 | 11 | 7 | 1 |
2 | 34 | 10 | 10 | 2 |
3 | 30 | 9 | 14 | 3 |
4 | 27 | 8 | 17 | 4 |
5 | 24 | 7 | 20 | 5 |
6 | 20 | 6 | 24 | 6 |
Related schemes
Source
GS1 EPC Tag Data Standard, Release 2.3, Ratified October 2025 - see Section 7.6 (Global Returnable Asset Identifier) and Section 14.6.4 for the encoding procedure. Read the EPC encoding guide for a full worked example of decoding hex to URI.