This code system http://hl7.org/fhir/citation-artifact-classifier defines the following codes:

CodeDisplayDefinition
audio Audio fileThe article cited is an audio file.
D001877 BookNon-periodical written or printed works consisting of sheets of pages fastened or bound together within covers.
cds-artifact Clinical Decision Support ArtifactThe artifact is used for decision support for healthcare decisions.
D016420 CommentComment
common-share Common ShareCitation Resource containing value added data that is openly shared
D019991 DatabaseA structured file of information or a set of logically related data stored and retrieved using computer-based means.
D064886 DatasetWorks consisting of organized collections of data, which have been stored permanently in a formalized manner suitable for communication, interpretation, or processing.
dataset-unpublished Dataset UnpublishedAn organized collection of data that is not stored permanently for communication.
Electronic Electronicthe journal is published in electronic format only
Electronic-eCollection Electronic-eCollectionused for electronic-only journals that publish individual articles first and then later collect them into an "issue" date that is typically called an eCollection.
Electronic-Print Electronic-Printthe journal is published first in electronic format followed by print (this value is currently used for just one journal, Nucleic Acids Research)
executable-app Executable appExecutable app
fhir-resource FHIR ResourceThe article cited is a FHIR resource.
image Image fileThe article cited is an image file.
interactive-form Interactive FormA user interface that supports data entry and data display.
D016428 Journal ArticleJournal Article
D016422 LetterLetter
machine-code Machine codeThe article cited is machine code.
medline-base Medline BaseCitation Resource containing only data from Medline
prediction-model Prediction ModelA formula or expression used to calculate an outcome representing a predicted result.
D000076942 PreprintScientific manuscript made available prior to PEER REVIEW.
Print Printthe journal is published in print format only
Print-Electronic Print Electronicthe journal is published in both print and electronic format
project-specific Project SpecificCitation Resource containing value added data specific to a project
protocol ProtocolThe article cited is the protocol of an activity and not the results or findings.
pseudocode PseudoCodeA non-executable, human-readable representation of software code.
D016425 Published ErratumPublished Erratum
standard-specification Standard SpecificationAn explicit set of requirements for an item, material, component, system or service, often used to define a technical standard which is an established norm or requirement for a repeatable technical task.
terminology TerminologyA structured set of codes and display values, which may be subtyped as a code system, value set, taxonomy, or ontology.
D059040 Video-Audio MediaUsed with articles which include video files or clips, or for articles which are entirely video.
webpage WebpageWebpage
<status value="draft"/><experimental value="true"/><date value="2021-03-11T10:55:11.085+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="Citation artifact classifier"/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/citation-artifact-classifier"/><content value="complete"/><concept><code value="audio"/><display value="Audio file"/><definition value="The article cited is an audio file."/></concept><concept><code value="D001877"/><display value="Book"/><definition value="Non-periodical written or printed works consisting of sheets of pages fastened or bound together within covers."/></concept><concept><code value="cds-artifact"/><display value="Clinical Decision Support Artifact"/><definition value="The artifact is used for decision support for healthcare decisions."/></concept><concept><code value="D016420"/><display value="Comment"/><definition value="Comment"/></concept><concept><code value="common-share"/><display value="Common Share"/><definition value="Citation Resource containing value added data that is openly shared"/></concept><concept><code value="D019991"/><display value="Database"/><definition value="A structured file of information or a set of logically related data stored and retrieved using computer-based means."/></concept><concept><code value="D064886"/><display value="Dataset"/><definition value="Works consisting of organized collections of data, which have been stored permanently in a formalized manner suitable for communication, interpretation, or processing."/></concept><concept><code value="dataset-unpublished"/><display value="Dataset Unpublished"/><definition value="An organized collection of data that is not stored permanently for communication."/></concept><concept><code value="Electronic"/><display value="Electronic"/><definition value="the journal is published in electronic format only"/></concept><concept><code value="Electronic-eCollection"/><display value="Electronic-eCollection"/><definition value="used for electronic-only journals that publish individual articles first and then later collect them into an "issue" date that is typically called an eCollection."/></concept><concept><code value="Electronic-Print"/><display value="Electronic-Print"/><definition value="the journal is published first in electronic format followed by print (this value is currently used for just one journal, Nucleic Acids Research)"/></concept><concept><code value="executable-app"/><display value="Executable app"/><definition value="Executable app"/></concept><concept><code value="fhir-resource"/><display value="FHIR Resource"/><definition value="The article cited is a FHIR resource."/></concept><concept><code value="image"/><display value="Image file"/><definition value="The article cited is an image file."/></concept><concept><code value="interactive-form"/><display value="Interactive Form"/><definition value="A user interface that supports data entry and data display."/></concept><concept><code value="D016428"/><display value="Journal Article"/><definition value="Journal Article"/></concept><concept><code value="D016422"/><display value="Letter"/><definition value="Letter"/></concept><concept><code value="machine-code"/><display value="Machine code"/><definition value="The article cited is machine code."/></concept><concept><code value="medline-base"/><display value="Medline Base"/><definition value="Citation Resource containing only data from Medline"/></concept><concept><code value="prediction-model"/><display value="Prediction Model"/><definition value="A formula or expression used to calculate an outcome representing a predicted result."/></concept><concept><code value="D000076942"/><display value="Preprint"/><definition value="Scientific manuscript made available prior to PEER REVIEW."/></concept><concept><code value="Print"/><display value="Print"/><definition value="the journal is published in print format only"/></concept><concept><code value="Print-Electronic"/><display value="Print Electronic"/><definition value="the journal is published in both print and electronic format"/></concept><concept><code value="project-specific"/><display value="Project Specific"/><definition value="Citation Resource containing value added data specific to a project"/></concept><concept><code value="protocol"/><display value="Protocol"/><definition value="The article cited is the protocol of an activity and not the results or findings."/></concept><concept><code value="pseudocode"/><display value="PseudoCode"/><definition value="A non-executable, human-readable representation of software code."/></concept><concept><code value="D016425"/><display value="Published Erratum"/><definition value="Published Erratum"/></concept><concept><code value="standard-specification"/><display value="Standard Specification"/><definition value="An explicit set of requirements for an item, material, component, system or service, often used to define a technical standard which is an established norm or requirement for a repeatable technical task."/></concept><concept><code value="terminology"/><display value="Terminology"/><definition value="A structured set of codes and display values, which may be subtyped as a code system, value set, taxonomy, or ontology."/></concept><concept><code value="D059040"/><display value="Video-Audio Media"/><definition value="Used with articles which include video files or clips, or for articles which are entirely video."/></concept><concept><code value="webpage"/><display value="Webpage"/><definition value="Webpage"/></concept></CodeSystem>