UTC standard identifiers (DS2 SG, 2020)
| Identifier | UTC standard |
|---|---|
| 0 | UTC as operated by the National Institute of Information and Communications Technology, Tokyo, Japan |
| 1 | UTC as operated by the U.S. National Institute of Standards and Technology |
| 2 | UTC as operated by the U.S. Naval Observatory |
| 3 | UTC as operated by the International Bureau ofWeights and Measures |
| 4 | Reserved for UTC as operated by a European laboratory |
| 5 | UTC as operated by the National Time Service Center, Chinese Academy of Sciences |
| 6 | Reserved |
| 7 | UTC not provided |
| 8 to 15 | Reserved for DFMC SBAS only |