> ## 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.

# Attachment

> Base StructureDefinition for Attachment Type: For referring to data content defined in other formats.

## Properties

| Name        | Required | Type                                                   | Description                                   |
| ----------- | -------- | ------------------------------------------------------ | --------------------------------------------- |
| id          | No       | string                                                 | Unique id for inter-element referencing       |
| extension   | No       | [Extension](/medical-api/fhir/data-types/extension)\[] | Additional content defined by implementations |
| contentType | No       | code                                                   | Mime type of the content, with charset etc.   |
| language    | No       | code                                                   | Human language of the content (BCP-47)        |
| data        | No       | base64Binary                                           | Data inline, base64ed                         |
| url         | No       | url                                                    | Uri where the data can be found               |
| size        | No       | unsignedInt                                            | Number of bytes of content (if url provided)  |
| hash        | No       | base64Binary                                           | Hash of the data (sha-1, base64ed)            |
| title       | No       | string                                                 | Label to display in place of the data         |
| creation    | No       | dateTime                                               | Date attachment was first created             |