Path | Short | Definition | Comments |
---|---|---|---|
Represents a library of quality improvement components | The Library resource is a general-purpose container for knowledge asset definitions. It can be used to describe and expose existing knowledge assets such as logic libraries and information model descriptions, as well as to describe a collection of knowledge assets. | ||
url | Canonical identifier for this library, represented as a URI (globally unique) | An absolute URI that is used to identify this library when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this library is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the library is stored on different servers. | Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found. |
identifier | Additional identifier for the library | A formal identifier that is used to identify this library when it is represented in other formats, or referenced in a specification, model, design or an instance. e.g. CMS or NQF identifiers for a measure artifact. Note that at least one identifier is required for non-experimental active artifacts. | Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this library outside of FHIR, where it is not possible to use the logical URI. |
version | Business version of the library | The identifier that is used to identify this version of the library when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the library author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. To provide a version consistent with the Decision Support Service specification, use the format Major.Minor.Revision (e.g. 1.0.0). For more information on versioning knowledge assets, refer to the Decision Support Service specification. Note that a version is required for non-experimental active artifacts. | There may be different library instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the library with the format [url]|[version]. |
name | Name for this library (computer friendly) | A natural language name identifying the library. This name should be usable as an identifier for the module by machine processing applications such as code generation. | The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly. |
title | Name for this library (human friendly) | A short, descriptive, user-friendly title for the library. | This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc. |
subtitle | Subordinate title of the library | An explanatory or alternate title for the library giving additional information about its content. | |
status | draft | active | retired | unknown | The status of this library. Enables tracking the life-cycle of the content. | Allows filtering of libraries that are appropriate for use vs. not. |
experimental | For testing purposes, not real usage | A Boolean value to indicate that this library is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage. | Allows filtering of librarys that are appropriate for use versus not. |
type | logic-library | model-definition | asset-collection | module-definition | Identifies the type of library such as a Logic Library, Model Definition, Asset Collection, or Module Definition. | |
subject[x] | Type of individual the library content is focused on | A code or group definition that describes the intended subject of the contents of the library. | |
date | Date last changed | The date (and optionally time) when the library was published. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the library changes. | Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the library. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource. |
publisher | Name of the publisher (organization or individual) | The name of the organization or individual that published the library. | Usually an organization but may be an individual. The publisher (or steward) of the library is the organization or individual primarily responsible for the maintenance and upkeep of the library. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the library. This item SHOULD be populated unless the information is available from context. |
contact | Contact details for the publisher | Contact details to assist a user in finding and communicating with the publisher. | May be a web site, an email address, a telephone number, etc. |
description | Natural language description of the library | A free text natural language description of the library from a consumer's perspective. | This description can be used to capture details such as why the library was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the library as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the library is presumed to be the predominant language in the place the library was created). |
useContext | The context that the content is intended to support | The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate library instances. | When multiple useContexts are specified, there is no expectation that all or any of the contexts apply. |
jurisdiction | Intended jurisdiction for library (if applicable) | A legal or geographic region in which the library is intended to be used. | It may be possible for the library to be used in jurisdictions other than those for which it was originally designed or intended. |
purpose | Why this library is defined | Explanation of why this library is needed and why it has been designed as it has. | This element does not describe the usage of the library. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this library. |
usage | Describes the clinical usage of the library | A detailed description of how the library is used from a clinical perspective. | |
copyright | Use and/or publishing restrictions | A copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library. | |
approvalDate | When the library was approved by publisher | The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage. | The 'date' element may be more recent than the approval date because of minor changes or editorial corrections. |
lastReviewDate | When the library was last reviewed | The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date. | If specified, this date follows the original approval date. |
effectivePeriod | When the library is expected to be used | The period during which the library content was or is planned to be in active use. | The effective period for a library determines when the content is applicable for usage and is independent of publication and review dates. For example, a measure intended to be used for the year 2016 might be published in 2015. |
topic | E.g. Education, Treatment, Assessment, etc. | Descriptive topics related to the content of the library. Topics provide a high-level categorization of the library that can be useful for filtering and searching. | |
author | Who authored the content | An individiual or organization primarily involved in the creation and maintenance of the content. | |
editor | Who edited the content | An individual or organization primarily responsible for internal coherence of the content. | |
reviewer | Who reviewed the content | An individual or organization primarily responsible for review of some aspect of the content. | |
endorser | Who endorsed the content | An individual or organization responsible for officially endorsing the content for use in some setting. | |
relatedArtifact | Additional documentation, citations, etc. | Related artifacts such as additional documentation, justification, or bibliographic references. | Each related artifact is either an attachment, or a reference to another resource, but not both. |
parameter | Parameters defined by the library | The parameter element defines parameters used by the library. | |
dataRequirement | What data is referenced by this library | Describes a set of data that must be provided in order to be able to successfully perform the computations defined by the library. | |
content | Contents of the library, either embedded or referenced | The content of the library as an Attachment. The content may be a reference to a url, or may be directly embedded as a base-64 string. Either way, the contentType of the attachment determines how to interpret the content. |
The Library resource is a general purpose container for clinical knowledge assets. These assets may be defined using a non-FHIR representation, such as a shareable library of clinical logic, written in Clinical Quality Language (CQL), or the XML Schema for an information model, or they may be defined using FHIR resources such as the description of a protocol represented by a PlanDefinition resource. In addition to representing the metadata of the library, the resource has elements for tracking dependencies, as well as for representing the parameters and data requirements for any expression functionality provided by the library.
For non-FHIR assets, the actual content of the library is represented using the Attachment data type, and may either be referenced with a URL, or the content may be embedded as a base-64 encoded string. Either way, the contentType
element of the attachment is used to indicate the representation of the library content.
Note that because the library content may be embedded as well as be retrievable from an external repository via the attachment URL, the possibility exists for the embedded content to be different from the content on the repository. With proper versioning and governance, this should never occur, but to minimize the potential impact of this possibility, implementers SHALL give precedence to the embedded content of a library when it is present.
The Library resource is definitional in nature, meaning it is intended to represent shareable knowledge independent of any particular patient. This is in contrast to the DocumentReference resource, which captures non-FHIR content related to a specific patient, and the Media and Binary resources which capture multimedia content and raw binary content, respectively.
composed-of | What resource is being referenced | Library.relatedArtifact.where(type='composed-of').resource |
content-type | The type of content in the library (e.g. text/cql) | Library.content.contentType |
context | A use context assigned to the library | (Library.useContext.value as CodeableConcept) |
context-quantity | A quantity- or range-valued use context assigned to the library | (Library.useContext.value as Quantity) | (Library.useContext.value as Range) |
context-type | A type of use context assigned to the library | Library.useContext.code |
date | The library publication date | Library.date |
depends-on | What resource is being referenced | Library.relatedArtifact.where(type='depends-on').resource |
derived-from | What resource is being referenced | Library.relatedArtifact.where(type='derived-from').resource |
description | The description of the library | Library.description |
effective | The time during which the library is intended to be in use | Library.effectivePeriod |
identifier | External identifier for the library | Library.identifier |
jurisdiction | Intended jurisdiction for the library | Library.jurisdiction |
name | Computationally friendly name of the library | Library.name |
predecessor | What resource is being referenced | Library.relatedArtifact.where(type='predecessor').resource |
publisher | Name of the publisher of the library | Library.publisher |
status | The current status of the library | Library.status |
successor | What resource is being referenced | Library.relatedArtifact.where(type='successor').resource |
title | The human-friendly name of the library | Library.title |
topic | Topics associated with the module | Library.topic |
type | The type of the library (e.g. logic-library, model-definition, asset-collection, module-definition) | Library.type |
url | The uri that identifies the library | Library.url |
version | The business version of the library | Library.version |
context-type-quantity | A use context type and quantity- or range-based value assigned to the library | Library.useContext |
context-type-value | A use context type and value assigned to the library | Library.useContext |
Enforces the minimum information set for the library metadata required by HL7 and other organizations that share and publish libraries
Path | Short | Definition | Comments |
---|---|---|---|
Represents a library of quality improvement components | The Library resource is a general-purpose container for knowledge asset definitions. It can be used to describe and expose existing knowledge assets such as logic libraries and information model descriptions, as well as to describe a collection of knowledge assets. | ||
url | Canonical identifier for this library, represented as a URI (globally unique) | An absolute URI that is used to identify this library when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this library is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the library is stored on different servers. | Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found. |
identifier | Additional identifier for the library | A formal identifier that is used to identify this library when it is represented in other formats, or referenced in a specification, model, design or an instance. e.g. CMS or NQF identifiers for a measure artifact. Note that at least one identifier is required for non-experimental active artifacts. | Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this library outside of FHIR, where it is not possible to use the logical URI. |
version | Business version of the library | The identifier that is used to identify this version of the library when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the library author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. To provide a version consistent with the Decision Support Service specification, use the format Major.Minor.Revision (e.g. 1.0.0). For more information on versioning knowledge assets, refer to the Decision Support Service specification. Note that a version is required for non-experimental active artifacts. | There may be different library instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the library with the format [url]|[version]. |
name | Name for this library (computer friendly) | A natural language name identifying the library. This name should be usable as an identifier for the module by machine processing applications such as code generation. | The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly. |
title | Name for this library (human friendly) | A short, descriptive, user-friendly title for the library. | This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc. |
subtitle | Subordinate title of the library | An explanatory or alternate title for the library giving additional information about its content. | |
status | draft | active | retired | unknown | The status of this library. Enables tracking the life-cycle of the content. | Allows filtering of libraries that are appropriate for use vs. not. |
experimental | For testing purposes, not real usage | A Boolean value to indicate that this library is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage. | Allows filtering of librarys that are appropriate for use versus not. |
type | logic-library | model-definition | asset-collection | module-definition | Identifies the type of library such as a Logic Library, Model Definition, Asset Collection, or Module Definition. | |
subject[x] | Type of individual the library content is focused on | A code or group definition that describes the intended subject of the contents of the library. | |
date | Date last changed | The date (and optionally time) when the library was published. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the library changes. | Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the library. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource. |
publisher | Name of the publisher (organization or individual) | The name of the organization or individual that published the library. | Usually an organization but may be an individual. The publisher (or steward) of the library is the organization or individual primarily responsible for the maintenance and upkeep of the library. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the library. This item SHOULD be populated unless the information is available from context. |
contact | Contact details for the publisher | Contact details to assist a user in finding and communicating with the publisher. | May be a web site, an email address, a telephone number, etc. |
description | Natural language description of the library | A free text natural language description of the library from a consumer's perspective. | This description can be used to capture details such as why the library was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the library as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the library is presumed to be the predominant language in the place the library was created). |
useContext | The context that the content is intended to support | The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate library instances. | When multiple useContexts are specified, there is no expectation that all or any of the contexts apply. |
jurisdiction | Intended jurisdiction for library (if applicable) | A legal or geographic region in which the library is intended to be used. | It may be possible for the library to be used in jurisdictions other than those for which it was originally designed or intended. |
purpose | Why this library is defined | Explanation of why this library is needed and why it has been designed as it has. | This element does not describe the usage of the library. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this library. |
usage | Describes the clinical usage of the library | A detailed description of how the library is used from a clinical perspective. | |
copyright | Use and/or publishing restrictions | A copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library. | |
approvalDate | When the library was approved by publisher | The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage. | The 'date' element may be more recent than the approval date because of minor changes or editorial corrections. |
lastReviewDate | When the library was last reviewed | The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date. | If specified, this date follows the original approval date. |
effectivePeriod | When the library is expected to be used | The period during which the library content was or is planned to be in active use. | The effective period for a library determines when the content is applicable for usage and is independent of publication and review dates. For example, a measure intended to be used for the year 2016 might be published in 2015. |
topic | E.g. Education, Treatment, Assessment, etc. | Descriptive topics related to the content of the library. Topics provide a high-level categorization of the library that can be useful for filtering and searching. | |
author | Who authored the content | An individiual or organization primarily involved in the creation and maintenance of the content. | |
editor | Who edited the content | An individual or organization primarily responsible for internal coherence of the content. | |
reviewer | Who reviewed the content | An individual or organization primarily responsible for review of some aspect of the content. | |
endorser | Who endorsed the content | An individual or organization responsible for officially endorsing the content for use in some setting. | |
relatedArtifact | Additional documentation, citations, etc. | Related artifacts such as additional documentation, justification, or bibliographic references. | Each related artifact is either an attachment, or a reference to another resource, but not both. |
parameter | Parameters defined by the library | The parameter element defines parameters used by the library. | |
dataRequirement | What data is referenced by this library | Describes a set of data that must be provided in order to be able to successfully perform the computations defined by the library. | |
content | Contents of the library, either embedded or referenced | The content of the library as an Attachment. The content may be a reference to a url, or may be directly embedded as a base-64 string. Either way, the contentType of the attachment determines how to interpret the content. |
Represents a CQL logic library
Path | Short | Definition | Comments |
---|---|---|---|
Represents a library of quality improvement components | The Library resource is a general-purpose container for knowledge asset definitions. It can be used to describe and expose existing knowledge assets such as logic libraries and information model descriptions, as well as to describe a collection of knowledge assets. | ||
url | Canonical identifier for this library, represented as a URI (globally unique) | An absolute URI that is used to identify this library when it is referenced in a specification, model, design or an instance; also called its canonical identifier. This SHOULD be globally unique and SHOULD be a literal address at which at which an authoritative instance of this library is (or will be) published. This URL can be the target of a canonical reference. It SHALL remain the same when the library is stored on different servers. | Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred. Multiple instances may share the same URL if they have a distinct version. The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author. Considerations for making this decision are found in [Technical and Business Versions](resource.html#versions). In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](resource.html#meta) element to indicate where the current master source of the resource can be found. |
identifier | Additional identifier for the library | A formal identifier that is used to identify this library when it is represented in other formats, or referenced in a specification, model, design or an instance. e.g. CMS or NQF identifiers for a measure artifact. Note that at least one identifier is required for non-experimental active artifacts. | Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this library outside of FHIR, where it is not possible to use the logical URI. |
version | Business version of the library | The identifier that is used to identify this version of the library when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the library author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. To provide a version consistent with the Decision Support Service specification, use the format Major.Minor.Revision (e.g. 1.0.0). For more information on versioning knowledge assets, refer to the Decision Support Service specification. Note that a version is required for non-experimental active artifacts. | There may be different library instances that have the same identifier but different versions. The version can be appended to the url in a reference to allow a reference to a particular business version of the library with the format [url]|[version]. |
name | Name for this library (computer friendly) | A natural language name identifying the library. This name should be usable as an identifier for the module by machine processing applications such as code generation. | The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly. |
title | Name for this library (human friendly) | A short, descriptive, user-friendly title for the library. | This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc. |
subtitle | Subordinate title of the library | An explanatory or alternate title for the library giving additional information about its content. | |
status | draft | active | retired | unknown | The status of this library. Enables tracking the life-cycle of the content. | Allows filtering of libraries that are appropriate for use vs. not. |
experimental | For testing purposes, not real usage | A Boolean value to indicate that this library is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage. | Allows filtering of librarys that are appropriate for use versus not. |
type | logic-library | model-definition | asset-collection | module-definition | Identifies the type of library such as a Logic Library, Model Definition, Asset Collection, or Module Definition. | |
subject[x] | Type of individual the library content is focused on | A code or group definition that describes the intended subject of the contents of the library. | |
date | Date last changed | The date (and optionally time) when the library was published. The date must change when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the library changes. | Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the library. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource. |
publisher | Name of the publisher (organization or individual) | The name of the organization or individual that published the library. | Usually an organization but may be an individual. The publisher (or steward) of the library is the organization or individual primarily responsible for the maintenance and upkeep of the library. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the library. This item SHOULD be populated unless the information is available from context. |
contact | Contact details for the publisher | Contact details to assist a user in finding and communicating with the publisher. | May be a web site, an email address, a telephone number, etc. |
description | Natural language description of the library | A free text natural language description of the library from a consumer's perspective. | This description can be used to capture details such as why the library was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the library as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the library is presumed to be the predominant language in the place the library was created). |
useContext | The context that the content is intended to support | The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate library instances. | When multiple useContexts are specified, there is no expectation that all or any of the contexts apply. |
jurisdiction | Intended jurisdiction for library (if applicable) | A legal or geographic region in which the library is intended to be used. | It may be possible for the library to be used in jurisdictions other than those for which it was originally designed or intended. |
purpose | Why this library is defined | Explanation of why this library is needed and why it has been designed as it has. | This element does not describe the usage of the library. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is. This may be used to point to source materials or specifications that drove the structure of this library. |
usage | Describes the clinical usage of the library | A detailed description of how the library is used from a clinical perspective. | |
copyright | Use and/or publishing restrictions | A copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library. | |
approvalDate | When the library was approved by publisher | The date on which the resource content was approved by the publisher. Approval happens once when the content is officially approved for usage. | The 'date' element may be more recent than the approval date because of minor changes or editorial corrections. |
lastReviewDate | When the library was last reviewed | The date on which the resource content was last reviewed. Review happens periodically after approval but does not change the original approval date. | If specified, this date follows the original approval date. |
effectivePeriod | When the library is expected to be used | The period during which the library content was or is planned to be in active use. | The effective period for a library determines when the content is applicable for usage and is independent of publication and review dates. For example, a measure intended to be used for the year 2016 might be published in 2015. |
topic | E.g. Education, Treatment, Assessment, etc. | Descriptive topics related to the content of the library. Topics provide a high-level categorization of the library that can be useful for filtering and searching. | |
author | Who authored the content | An individiual or organization primarily involved in the creation and maintenance of the content. | |
editor | Who edited the content | An individual or organization primarily responsible for internal coherence of the content. | |
reviewer | Who reviewed the content | An individual or organization primarily responsible for review of some aspect of the content. | |
endorser | Who endorsed the content | An individual or organization responsible for officially endorsing the content for use in some setting. | |
relatedArtifact | Additional documentation, citations, etc. | Related artifacts such as additional documentation, justification, or bibliographic references. | Each related artifact is either an attachment, or a reference to another resource, but not both. |
parameter | Parameters defined by the library | The parameter element defines parameters used by the library. | |
dataRequirement | What data is referenced by this library | Describes a set of data that must be provided in order to be able to successfully perform the computations defined by the library. | |
content | Contents of the library, either embedded or referenced | The content of the library as an Attachment. The content may be a reference to a url, or may be directly embedded as a base-64 string. Either way, the contentType of the attachment determines how to interpret the content. |