Abstract	The article itself is an abstract (of a paper or presentation) that usually has been presented or published separately.
Announcement	Material announced in the publication (may or may not be directly related to the publication)
Article Commentary	A work whose subject or focus is another article or articles; this article comments on the other article(s). (This value would be used when the editors of a publication invite an author with an opposing opinion to comment on a controversial article, and then publish the two together. The somewhat similar value “editorial” is reserved for commentary written by an editor or other publication staff.)
Book Review	Review or analysis of one or more printed or online books (The similar value “product-review” is used for product analyses.)
Books Received	Notification that items, e.g., books or other works, have been received by a publication for review or other consideration
Brief Report	A short and/or rapid announcement of research results
Calendar	A list of events
Case Report	Case study, case report, or other description of a case
Collection	Wrapper article for a series of sub-articles or responses; this value’s usage is restricted to articles whose intellectual content appears primarily in sub-article or response.
Discussion	Invited discussion related to a specific article or issue
Dissertation	Thesis or dissertation written as part of the completion of a degree of study
Editorial	Opinion piece, policy statement, or general commentary, typically written by staff of the publication (The similar value “article-commentary” is reserved for a commentary on a specific article or articles, which is written by an author with a contrasting position, not an editor or other publication staff.)
In Brief	Summary or teaser of items in the current issue
Introduction	An introduction to a publication, or to a series of articles within a publication, etc., typically for a special section or issue
Letter	Letter to a publication, typically commenting upon a published work
Meeting Report	Report of a conference, symposium, or meeting
News	News item, normally current but atypically historical
Obituary	Announcement of a death, or the appreciation for a colleague who has recently died
Oration	Reprint of a speech or oral presentation
Partial Retraction	Retraction or disavowal of part(s) of previously published material
Product Review	Description, analysis, or review of a product or service, for example, a software package (The similar value “book-review” is used for analyses of books.)
Rapid Communication	Fast-breaking research update or other news item
Reply	Reply to a letter or commentary, typically by the original author commenting upon the comments
Reprint	Reprint of a previously published article
Research Article	Article reporting on primary research (The related value “review-article” describes a literature review, research summary, or state-of-the-art article.) Clinical trials is categorised in this group.
Retraction	Retraction or disavowal of previously published material
Review Article	Review or state-of-the-art summary article (The related value “research-article” describes original research.) Systematic review or Meta analysis is categorised in this type.
Translation	Translation of an article originally produced in a different language
Methods Article	Study protocol articles can be for proposed or ongoing prospective clinical research, and should provide a detailed account of the hypothesis, rationale and methodology of the study.
Corrections	A modification or correction of previously published material; this is sometimes called “errata”.