Resource type: library

Description

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.

Elements

PathShortDefinitionComments
Represents a library of quality improvement componentsThe 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.
urlCanonical 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.
identifierAdditional identifier for the libraryA 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.
versionBusiness version of the libraryThe 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].
nameName 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.
titleName 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.
subtitleSubordinate title of the libraryAn explanatory or alternate title for the library giving additional information about its content.
statusdraft | active | retired | unknownThe status of this library. Enables tracking the life-cycle of the content.Allows filtering of libraries that are appropriate for use vs. not.
experimentalFor testing purposes, not real usageA 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.
typelogic-library | model-definition | asset-collection | module-definitionIdentifies 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 onA code or group definition that describes the intended subject of the contents of the library.
dateDate last changedThe 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.
publisherName 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.
contactContact details for the publisherContact details to assist a user in finding and communicating with the publisher.May be a web site, an email address, a telephone number, etc.
descriptionNatural language description of the libraryA 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).
useContextThe context that the content is intended to supportThe 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.
jurisdictionIntended 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.
purposeWhy this library is definedExplanation 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.
usageDescribes the clinical usage of the libraryA detailed description of how the library is used from a clinical perspective.
copyrightUse and/or publishing restrictionsA copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library.
approvalDateWhen the library was approved by publisherThe 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.
lastReviewDateWhen the library was last reviewedThe 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.
effectivePeriodWhen the library is expected to be usedThe 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.
topicE.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.
authorWho authored the contentAn individiual or organization primarily involved in the creation and maintenance of the content.
editorWho edited the contentAn individual or organization primarily responsible for internal coherence of the content.
reviewerWho reviewed the contentAn individual or organization primarily responsible for review of some aspect of the content.
endorserWho endorsed the contentAn individual or organization responsible for officially endorsing the content for use in some setting.
relatedArtifactAdditional 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.
parameterParameters defined by the libraryThe parameter element defines parameters used by the library.
dataRequirementWhat data is referenced by this libraryDescribes a set of data that must be provided in order to be able to successfully perform the computations defined by the library.
contentContents of the library, either embedded or referencedThe 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.

Scope and Usage

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.

Boundaries and Relationships

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.

Search Parameters

composed-ofWhat resource is being referencedLibrary.relatedArtifact.where(type='composed-of').resource
content-typeThe type of content in the library (e.g. text/cql)Library.content.contentType
contextA use context assigned to the library(Library.useContext.value as CodeableConcept)
context-quantityA quantity- or range-valued use context assigned to the library(Library.useContext.value as Quantity) | (Library.useContext.value as Range)
context-typeA type of use context assigned to the libraryLibrary.useContext.code
dateThe library publication dateLibrary.date
depends-onWhat resource is being referencedLibrary.relatedArtifact.where(type='depends-on').resource
derived-fromWhat resource is being referencedLibrary.relatedArtifact.where(type='derived-from').resource
descriptionThe description of the libraryLibrary.description
effectiveThe time during which the library is intended to be in useLibrary.effectivePeriod
identifierExternal identifier for the libraryLibrary.identifier
jurisdictionIntended jurisdiction for the libraryLibrary.jurisdiction
nameComputationally friendly name of the libraryLibrary.name
predecessorWhat resource is being referencedLibrary.relatedArtifact.where(type='predecessor').resource
publisherName of the publisher of the libraryLibrary.publisher
statusThe current status of the libraryLibrary.status
successorWhat resource is being referencedLibrary.relatedArtifact.where(type='successor').resource
titleThe human-friendly name of the libraryLibrary.title
topicTopics associated with the moduleLibrary.topic
typeThe type of the library (e.g. logic-library, model-definition, asset-collection, module-definition)Library.type
urlThe uri that identifies the libraryLibrary.url
versionThe business version of the libraryLibrary.version
context-type-quantityA use context type and quantity- or range-based value assigned to the libraryLibrary.useContext
context-type-valueA use context type and value assigned to the libraryLibrary.useContext

Extension Definitions

These are extension definitions for this resource defined by the spec

Profiles based on this resource

Shareable Library

Enforces the minimum information set for the library metadata required by HL7 and other organizations that share and publish libraries

Elements

PathShortDefinitionComments
Represents a library of quality improvement componentsThe 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.
urlCanonical 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.
identifierAdditional identifier for the libraryA 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.
versionBusiness version of the libraryThe 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].
nameName 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.
titleName 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.
subtitleSubordinate title of the libraryAn explanatory or alternate title for the library giving additional information about its content.
statusdraft | active | retired | unknownThe status of this library. Enables tracking the life-cycle of the content.Allows filtering of libraries that are appropriate for use vs. not.
experimentalFor testing purposes, not real usageA 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.
typelogic-library | model-definition | asset-collection | module-definitionIdentifies 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 onA code or group definition that describes the intended subject of the contents of the library.
dateDate last changedThe 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.
publisherName 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.
contactContact details for the publisherContact details to assist a user in finding and communicating with the publisher.May be a web site, an email address, a telephone number, etc.
descriptionNatural language description of the libraryA 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).
useContextThe context that the content is intended to supportThe 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.
jurisdictionIntended 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.
purposeWhy this library is definedExplanation 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.
usageDescribes the clinical usage of the libraryA detailed description of how the library is used from a clinical perspective.
copyrightUse and/or publishing restrictionsA copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library.
approvalDateWhen the library was approved by publisherThe 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.
lastReviewDateWhen the library was last reviewedThe 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.
effectivePeriodWhen the library is expected to be usedThe 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.
topicE.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.
authorWho authored the contentAn individiual or organization primarily involved in the creation and maintenance of the content.
editorWho edited the contentAn individual or organization primarily responsible for internal coherence of the content.
reviewerWho reviewed the contentAn individual or organization primarily responsible for review of some aspect of the content.
endorserWho endorsed the contentAn individual or organization responsible for officially endorsing the content for use in some setting.
relatedArtifactAdditional 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.
parameterParameters defined by the libraryThe parameter element defines parameters used by the library.
dataRequirementWhat data is referenced by this libraryDescribes a set of data that must be provided in order to be able to successfully perform the computations defined by the library.
contentContents of the library, either embedded or referencedThe 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.

CQL Library

Represents a CQL logic library

Elements

PathShortDefinitionComments
Represents a library of quality improvement componentsThe 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.
urlCanonical 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.
identifierAdditional identifier for the libraryA 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.
versionBusiness version of the libraryThe 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].
nameName 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.
titleName 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.
subtitleSubordinate title of the libraryAn explanatory or alternate title for the library giving additional information about its content.
statusdraft | active | retired | unknownThe status of this library. Enables tracking the life-cycle of the content.Allows filtering of libraries that are appropriate for use vs. not.
experimentalFor testing purposes, not real usageA 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.
typelogic-library | model-definition | asset-collection | module-definitionIdentifies 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 onA code or group definition that describes the intended subject of the contents of the library.
dateDate last changedThe 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.
publisherName 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.
contactContact details for the publisherContact details to assist a user in finding and communicating with the publisher.May be a web site, an email address, a telephone number, etc.
descriptionNatural language description of the libraryA 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).
useContextThe context that the content is intended to supportThe 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.
jurisdictionIntended 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.
purposeWhy this library is definedExplanation 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.
usageDescribes the clinical usage of the libraryA detailed description of how the library is used from a clinical perspective.
copyrightUse and/or publishing restrictionsA copyright statement relating to the library and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the library.
approvalDateWhen the library was approved by publisherThe 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.
lastReviewDateWhen the library was last reviewedThe 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.
effectivePeriodWhen the library is expected to be usedThe 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.
topicE.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.
authorWho authored the contentAn individiual or organization primarily involved in the creation and maintenance of the content.
editorWho edited the contentAn individual or organization primarily responsible for internal coherence of the content.
reviewerWho reviewed the contentAn individual or organization primarily responsible for review of some aspect of the content.
endorserWho endorsed the contentAn individual or organization responsible for officially endorsing the content for use in some setting.
relatedArtifactAdditional 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.
parameterParameters defined by the libraryThe parameter element defines parameters used by the library.
dataRequirementWhat data is referenced by this libraryDescribes a set of data that must be provided in order to be able to successfully perform the computations defined by the library.
contentContents of the library, either embedded or referencedThe 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.