> ## 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. # EventDefinition > The EventDefinition resource provides a reusable description of when a particular event can occur. ## Properties | Name | Required | Type | Description | | --------------- | -------- | ----------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------- | | url | No | uri | Canonical identifier for this event definition, represented as a URI (globally unique) | | identifier | No | [Identifier](/medical-api/fhir/data-types/identifier)\[] | Additional identifier for the event definition | | version | No | string | Business version of the event definition | | name | No | string | Name for this event definition (computer friendly) | | title | No | string | Name for this event definition (human friendly) | | subtitle | No | string | Subordinate title of the event definition | | status | Yes | code | draft / active / retired / unknown | | experimental | No | boolean | For testing purposes, not real usage | | subject\[x] | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept), Reference\<[Group](/medical-api/fhir/resources/group)> | Type of individual the event definition is focused on | | date | No | dateTime | Date last changed | | publisher | No | string | Name of the publisher (organization or individual) | | contact | No | [ContactDetail](/medical-api/fhir/data-types/contactdetail)\[] | Contact details for the publisher | | description | No | markdown | Natural language description of the event definition | | useContext | No | [UsageContext](/medical-api/fhir/data-types/usagecontext)\[] | The context that the content is intended to support | | jurisdiction | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept)\[] | Intended jurisdiction for event definition (if applicable) | | purpose | No | markdown | Why this event definition is defined | | usage | No | string | Describes the clinical usage of the event definition | | copyright | No | markdown | Use and/or publishing restrictions | | approvalDate | No | date | When the event definition was approved by publisher | | lastReviewDate | No | date | When the event definition was last reviewed | | effectivePeriod | No | [Period](/medical-api/fhir/data-types/period) | When the event definition is expected to be used | | topic | No | [CodeableConcept](/medical-api/fhir/data-types/codeableconcept)\[] | E.g. Education, Treatment, Assessment, etc. | | author | No | [ContactDetail](/medical-api/fhir/data-types/contactdetail)\[] | Who authored the content | | editor | No | [ContactDetail](/medical-api/fhir/data-types/contactdetail)\[] | Who edited the content | | reviewer | No | [ContactDetail](/medical-api/fhir/data-types/contactdetail)\[] | Who reviewed the content | | endorser | No | [ContactDetail](/medical-api/fhir/data-types/contactdetail)\[] | Who endorsed the content | | relatedArtifact | No | [RelatedArtifact](/medical-api/fhir/data-types/relatedartifact)\[] | Additional documentation, citations, etc. | | trigger | Yes | [TriggerDefinition](/medical-api/fhir/data-types/triggerdefinition)\[] | "when" the event occurs (multiple = 'or') | ## Search Parameters | Name | Type | Description | Expression | | --------------------- | --------- | -------------------------------------------------------------------------------------- | -------------------------------- | | composed-of | reference | What resource is being referenced | EventDefinition.relatedArtifact | | context | token | A use context assigned to the event definition | EventDefinition.useContext.value | | context-quantity | quantity | A quantity- or range-valued use context assigned to the event definition | EventDefinition.useContext.value | | context-type | token | A type of use context assigned to the event definition | EventDefinition.useContext.code | | date | date | The event definition publication date | EventDefinition.date | | depends-on | reference | What resource is being referenced | EventDefinition.relatedArtifact | | derived-from | reference | What resource is being referenced | EventDefinition.relatedArtifact | | description | string | The description of the event definition | EventDefinition.description | | effective | date | The time during which the event definition is intended to be in use | EventDefinition.effectivePeriod | | identifier | token | External identifier for the event definition | EventDefinition.identifier | | jurisdiction | token | Intended jurisdiction for the event definition | EventDefinition.jurisdiction | | name | string | Computationally friendly name of the event definition | EventDefinition.name | | predecessor | reference | What resource is being referenced | EventDefinition.relatedArtifact | | publisher | string | Name of the publisher of the event definition | EventDefinition.publisher | | status | token | The current status of the event definition | EventDefinition.status | | successor | reference | What resource is being referenced | EventDefinition.relatedArtifact | | title | string | The human-friendly name of the event definition | EventDefinition.title | | topic | token | Topics associated with the module | EventDefinition.topic | | url | uri | The uri that identifies the event definition | EventDefinition.url | | version | token | The business version of the event definition | EventDefinition.version | | context-type-quantity | composite | A use context type and quantity- or range-based value assigned to the event definition | EventDefinition.useContext | | context-type-value | composite | A use context type and value assigned to the event definition | EventDefinition.useContext | ## 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 [EventDefinition](https://www.hl7.org/fhir/StructureDefinition/EventDefinition).