Extension 
url 
value[x] 
valueDate
valuePeriod Documentation for this formatThis is the set of resources that conform to either of the profiles CertificationEffectiveDate (http://hl7.org/fhir/us/davinci-pas/StructureDefinition/extension-itemCertificationEffectiveDate) and CertificationEffectiveDate (http://hl7.org/fhir/us/davinci-pas/StructureDefinition/extension-itemCertificationEffectiveDate). E.g. what you have to deal with if you get resources conforming to one of them
| Name | Flags | Card. | Type | Description & Constraints Filter: |
|---|---|---|---|---|
| Extension | 0..* | Extension | ||
| url | 1..1 | uri | identifies the meaning of the extension | |
| value[x] | 0..1 | Value of extension | ||
| valueDate | date | |||
| valuePeriod | Period | |||
| Documentation for this format | ||||