| id | No | string | Unique id for inter-element referencing |
| extension | No | Extension[] | Additional content defined by implementations |
| type | Yes | Coding[] | Indication of the reason the entity signed the object(s) |
| when | Yes | instant | When the signature was created |
| who | Yes | Reference<Practitioner / PractitionerRole / RelatedPerson / Patient / Device / Organization> | Who signed |
| onBehalfOf | No | Reference<Practitioner / PractitionerRole / RelatedPerson / Patient / Device / Organization> | The party represented |
| targetFormat | No | code | The technical format of the signed resources |
| sigFormat | No | code | The technical format of the signature |
| data | No | base64Binary | The actual signature content (XML DigSig. JWS, picture, etc.) |
