SearchModifierCode

This code system http://hl7.org/fhir/search-modifier-code defines the following codes:

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.).