SGHI FHIR Profile Implementation Guide
0.1.0 - ci-build

SGHI FHIR Profile Implementation Guide, published by Kathurima Kimathi. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/savannahghi/sil_fhir_profile_ig/ and changes regularly. See the Directory of published versions

## Data Type Profile: SGHIAttachment - Detailed Descriptions

Draft as of 2026-05-21

Definitions for the attachment data type profile.

- Key Elements Table
- Differential Elements Table
- Snapshot Elements Table

Guidance on how to interpret the contents of this table can be foundhere

0. Attachment
Definition | For referring to data content defined in other formats.
Short | Content in a format defined elsewhere
Comments | When providing a summary view (for example with Observation.value[x]) Attachment should be represented with a brief display text such as "Signed Procedure Consent".
Control | 0..*
Is Modifier | false
Invariants | att-1: If the Attachment has data, it SHALL have a contentType (data.empty() or contentType.exists()) ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
2. Attachment.contentType
Definition | Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.
Short | Mime type of the content, with charset etc.
Control | 10..1 This element is affected by the following invariants: att-1
Binding | The codes SHALL be taken from MimeTypes http://hl7.org/fhir/ValueSet/mimetypes|5.0.0 (required to `http://hl7.org/fhir/ValueSet/mimetypes|5.0.0` ) BCP 13 (RFCs 2045, 2046, 2047, 4288, 4289 and 2049)
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Processors of the data need to be able to know how to interpret the data.
Pattern Value | `application/json`
Example | General: text/plain; charset=UTF-8, image/png
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
4. Attachment.url
Definition | A location where the data can be accessed.
Short | Uri where the data can be found
Comments | If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.
Control | 10..1
Type | url
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | The data needs to be transmitted by reference.
Example | General: http://www.acme.com/logo-small.png
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
6. Attachment.creation
Definition | The date that the attachment was first created.
Short | Date attachment was first created
Control | 10..1
Type | dateTime
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | This is often tracked as an integrity issue for use of the attachment.
Invariants | ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

Guidance on how to interpret the contents of this table can be foundhere

0. Attachment
2. Attachment.contentType
Control | 1..?
Pattern Value | `application/json`
4. Attachment.url
Control | 1..?
6. Attachment.creation
Control | 1..?

Guidance on how to interpret the contents of this table can be foundhere

0. Attachment
Definition | For referring to data content defined in other formats.
Short | Content in a format defined elsewhere
Comments | When providing a summary view (for example with Observation.value[x]) Attachment should be represented with a brief display text such as "Signed Procedure Consent".
Control | 0..*
Is Modifier | false
Invariants | att-1: If the Attachment has data, it SHALL have a contentType (`data.empty() or contentType.exists()`) ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
2. Attachment.id
Definition | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short | Unique id for inter-element referencing
Control | 0..1 This element is affected by the following invariants: ele-1
Type | id
Is Modifier | false
XML Format | In the XML format, this property is represented as an attribute.
Summary | false
4. Attachment.extension
Definition | May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.
Short | Additional content defined by implementations
Comments | There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.
Control | 0..*
Type | Extension
Is Modifier | false
Summary | false
Alternate Names | extensions, user content
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing | This element introduces a set of slices on `Attachment.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
6. Attachment.contentType
Definition | Identifies the type of the data in the attachment and allows a method to be chosen to interpret or render the data. Includes mime type parameters such as charset where appropriate.
Short | Mime type of the content, with charset etc.
Control | 1..1 This element is affected by the following invariants: att-1
Binding | The codes SHALL be taken from MimeTypes (required to `http://hl7.org/fhir/ValueSet/mimetypes|5.0.0` ) BCP 13 (RFCs 2045, 2046, 2047, 4288, 4289 and 2049)
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Processors of the data need to be able to know how to interpret the data.
Pattern Value | `application/json`
Example | General: text/plain; charset=UTF-8, image/png
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
8. Attachment.language
Definition | The human language of the content. The value can be any valid value according to BCP 47.
Short | Human language of the content (BCP-47)
Control | 0..1
Binding | The codes SHALL be taken from AllLanguages (required to `http://hl7.org/fhir/ValueSet/all-languages|5.0.0` ) IETF language tag for a human language.
Type | code
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Users need to be able to choose between the languages in a set of attachments.
Example | General: en-AU
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
10. Attachment.data
Definition | The actual data of the attachment - a sequence of bytes, base64 encoded.
Short | Data inline, base64ed
Comments | The base64-encoded data SHALL be expressed in the same character set as the base resource XML or JSON.
Control | 0..1 This element is affected by the following invariants: att-1
Type | base64Binary
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Requirements | The data needs to able to be transmitted inline.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
12. Attachment.url
Definition | A location where the data can be accessed.
Short | Uri where the data can be found
Comments | If both data and url are provided, the url SHALL point to the same content as the data contains. Urls may be relative references or may reference transient locations such as a wrapping envelope using cid: though this has ramifications for using signatures. Relative URLs are interpreted relative to the service url, like a resource reference, rather than relative to the resource itself. If a URL is provided, it SHALL resolve to actual data.
Control | 1..1
Type | url
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | The data needs to be transmitted by reference.
Example | General: http://www.acme.com/logo-small.png
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
14. Attachment.size
Definition | The number of bytes of data that make up this attachment (before base64 encoding, if that is done).
Short | Number of bytes of content (if url provided)
Comments | The number of bytes is redundant if the data is provided as a base64binary, but is useful if the data is provided as a url reference.
Control | 0..1
Type | integer64
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Representing the size allows applications to determine whether they should fetch the content automatically in advance, or refuse to fetch it at all.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
16. Attachment.hash
Definition | The calculated hash of the data using SHA-1. Represented using base64.
Short | Hash of the data (sha-1, base64ed)
Comments | The hash is calculated on the data prior to base64 encoding, if the data is based64 encoded. The hash is not intended to support digital signatures. Where protection against malicious threats a digital signature should be considered, see Provenance.signature for mechanism to protect a resource with a digital signature.
Control | 0..1
Type | base64Binary
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Included so that applications can verify that the contents of a location have not changed due to technical failures (e.g., storage rot, transport glitch, incorrect version).
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
18. Attachment.title
Definition | A label or set of text to display in place of the data.
Short | Label to display in place of the data
Comments | May sometimes be derived from the source filename.
Control | 0..1
Type | string
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | Applications need a label to display to a human user in place of the actual data if the data cannot be rendered or perceived by the viewer.
Example | General: Official Corporate Logo
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
20. Attachment.creation
Definition | The date that the attachment was first created.
Short | Date attachment was first created
Control | 1..1
Type | dateTime
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | true
Requirements | This is often tracked as an integrity issue for use of the attachment.
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
22. Attachment.height
Definition | Height of the image in pixels (photo/video).
Short | Height of the image in pixels (photo/video)
Control | 0..1
Type | positiveInt
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
24. Attachment.width
Definition | Width of the image in pixels (photo/video).
Short | Width of the image in pixels (photo/video)
Control | 0..1
Type | positiveInt
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
26. Attachment.frames
Definition | The number of frames in a photo. This is used with a multi-page fax, or an imaging acquisition context that takes multiple slices in a single image, or an animated gif. If there is more than one frame, this SHALL have a value in order to alert interface software that a multi-frame capable rendering widget is required.
Short | Number of frames if > 1 (photo)
Comments | if the number of frames is not supplied, the value may be unknown. Applications should not assume that there is only one frame unless it is explicitly stated.
Control | 0..1
Type | positiveInt
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
28. Attachment.duration
Definition | The duration of the recording in seconds - for audio and video.
Short | Length in seconds (audio / video)
Comments | The duration might differ from occurrencePeriod if recording was paused.
Control | 0..1
Type | decimal
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
30. Attachment.pages
Definition | The number of pages when printed.
Short | Number of printed pages
Control | 0..1
Type | positiveInt
Is Modifier | false
Primitive Value | This primitive element may be present, or absent, or replaced by an extension
Summary | false
Invariants | ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)