| Code | Display | Definition |
| missing | Missing | The search parameter returns resources that have a value or not. |
| exact | Exact | The search parameter returns resources that have a value that exactly matches the supplied parameter (the whole string, including casing and accents). |
| contains | Contains | The search parameter returns resources that include the supplied parameter value anywhere within the field being searched. |
| not | Not | The search parameter returns resources that do not contain a match. |
| text | Text | The search parameter is processed as a string that searches text associated with the code/value - either CodeableConcept.text, Coding.display, or Identifier.type.text. |
| in | In | The search parameter is a URI (relative or absolute) that identifies a value set, and the search parameter tests whether the coding is in the specified value set. |
| not-in | Not In | The search parameter is a URI (relative or absolute) that identifies a value set, and the search parameter tests whether the coding is not in the specified value set. |
| below | Below | The search parameter tests whether the value in a resource is subsumed by the specified value (is-a, or hierarchical relationships). |
| above | Above | The search parameter tests whether the value in a resource subsumes the specified value (is-a, or hierarchical relationships). |
| type | Type | The search parameter only applies to the Resource Type specified as a modifier (e.g. the modifier is not actually :type, but :Patient etc.). |
