> ## Documentation Index > Fetch the complete documentation index at: https://docs.metriport.com/llms.txt > Use this file to discover all available pages before exploring further. # Group > Represents a defined collection of entities that may be discussed or acted upon collectively but which are not expected to act collectively, and are not formally or legally recognized; i.e. a collection of entities that isn't an Organization. ## Properties | Name | Required | Type | Description | | ------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------- | | identifier | No | [Identifier](/medical-api/fhir/data-types/identifier)\[] | Unique id | | active | No | boolean | Whether this group's record is in active use | | type | Yes | code | person / animal / practitioner / device / medication / substance | | actual | Yes | boolean | Descriptive or actual | | code | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | Kind of Group members | | name | No | string | Label for Group | | quantity | No | unsignedInt | Number of members | | managingEntity | No | Reference\<[Organization](/medical-api/fhir/resources/organization) / [RelatedPerson](/medical-api/fhir/resources/relatedperson) / [Practitioner](/medical-api/fhir/resources/practitioner) / [PractitionerRole](/medical-api/fhir/resources/practitionerrole)> | Entity that is the custodian of the Group's definition | | characteristic | No | GroupCharacteristic | Include / Exclude group members by Trait | | - id | No | string | Unique id for inter-element referencing | | - extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations | | - modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored even if unrecognized | | - code | Yes | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept) | Kind of characteristic | | - value\[x] | Yes | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept), boolean, [Quantity](/medical-api/fhir/data-types/quantity), [Range](/medical-api/fhir/data-types/range), Reference\<> | Value held by characteristic | | - exclude | Yes | boolean | Group includes or excludes | | - period | No | [Period](/medical-api/fhir/data-types/period) | Period over which characteristic is tested | | member | No | GroupMember | Who or what is in group | | - id | No | string | Unique id for inter-element referencing | | - extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations | | - modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored even if unrecognized | | - entity | Yes | Reference\<[Patient](/medical-api/fhir/resources/patient) / [Practitioner](/medical-api/fhir/resources/practitioner) / [PractitionerRole](/medical-api/fhir/resources/practitionerrole) / [Device](/medical-api/fhir/resources/device) / [Medication](/medical-api/fhir/resources/medication) / [Substance](/medical-api/fhir/resources/substance) / [Group](/medical-api/fhir/resources/group)> | Reference to the group member | | - period | No | [Period](/medical-api/fhir/data-types/period) | Period member belonged to the group | | - inactive | No | boolean | If member is no longer in group | ## Search Parameters | Name | Type | Description | Expression | | -------------------- | --------- | ------------------------------------------------------ | ---------------------------- | | actual | token | Descriptive or actual | Group.actual | | characteristic | token | Kind of characteristic | Group.characteristic.code | | code | token | The kind of resources contained | Group.code | | exclude | token | Group includes or excludes | Group.characteristic.exclude | | identifier | token | Unique id | Group.identifier | | managing-entity | reference | Entity that is the custodian of the Group's definition | Group.managingEntity | | member | reference | Reference to the group member | Group.member.entity | | type | token | The type of resources the group contains | Group.type | | value | token | Value held by characteristic | Group.characteristic.value | | characteristic-value | composite | A composite of both characteristic and value | Group.characteristic | ## Inherited Properties | Name | Required | Type | Description | | ----------------- | -------- | ------------------------------------------------------ | ------------------------------------------------------ | | id | No | string | Logical id of this artifact | | meta | No | [Meta](/medical-api/fhir/data-types/meta) | Metadata about the resource | | implicitRules | No | uri | A set of rules under which this content was created | | language | No | code | Language of the resource content | | text | No | [Narrative](/medical-api/fhir/data-types/narrative) | Text summary of the resource, for human interpretation | | contained | No | Resource\[] | Contained, inline Resources | | extension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations | | modifierExtension | No | [Extension](/medical-api/fhir/data-types/extension)\[] | Extensions that cannot be ignored | To view the FHIR specification for this resource, see [Group](https://www.hl7.org/fhir/StructureDefinition/Group).