List 228: Grant identifier type
| Value | Description | Notes | Issue number | Modified in Issue |
|---|---|---|---|---|
| 01 | Proprietary | Note that <IDTypeName> is required with proprietary identifiers | 33 | |
| 06 | DOI | Digital Object Identifier (variable length and character set, beginning ‘10.’ and without https://doi.org/ or the older http://dx.doi.org/) | 65 |