FAQs for Publishers

What are a publisher’s options for depositing articles in PMC?

A publisher has three participation options for including a journal in PMC:

  1. Full Participation: the publisher commits to depositing the complete contents of each issue or volume of a journal, starting with a particular volume/issue or publication date.
  2. NIH Portfolio: the publisher commits to depositing all NIH-funded articles for a journal as defined by the NIH Public Access Policy, starting with a particular volume/issue or publication date. The publisher may choose to also deposit other, non-NIH-funded articles for the journal.
  3. Selective Deposit: the publisher deposits a selected set of articles to PMC for a journal. This is generally used by publishers for journals that offer a hybrid publishing model, i.e., a traditional subscription-based journal in which only selected articles are published as open access. This option may also be used for other sets of articles that are more limited than those covered by a full participation or NIH portfolio agreement. Collections of these selective deposit journals, often grouped by publisher, are referred to in PMC as Special Collections. A list of Special Collections and the journals in each collection can be found on the Journal list page under the Special Collections tab.

All three options require the completion of a formal participation agreement with NLM and the deposit of full-text XML and associated files for the final published versions of the articles. See Add a Journal to PMC for details.

Author manuscripts cannot be deposited directly in PMC. Final peer-reviewed manuscripts should be deposited in PMC via the NIHMS upon acceptance for publication. Publishers who wish to deposit manuscripts to help their authors comply with the NIH Public Access Policy should refer to the description of submission methods on the Public Access site and the Publisher FAQ on the NIHMS site.

How soon after publication must articles be made available through PMC?

Publishers are encouraged to make their content viewable in PMC at the time of publication, or soon after, but may choose to have a release delay (embargo) for up to a year or more. See “Full Text Deposit and Access” on the PMC Policies page for further details.

Who controls copyright privileges for the material archived in PMC?

Copyright to all material deposited in PMC remains with the publisher or individual authors, whichever is applicable. PMC is an archive and does not claim copyright on any material in the archive. For more information, see the PMC Copyright Notice.

In what electronic formats may data be submitted to PMC?

A journal must provide PMC the full text of articles in an XML format that conforms to an acceptable journal article DTD (Document Type Definition). PMC does not accept articles in HTML format. The original high-resolution, digital image files must also be provided for all figures. A PDF version, if one exists, must be deposited in PMC in addition to the XML version (but not as the only form) of an article. Supplementary material, in the form of video, audio or data files that may be available with an article, must also be deposited. See the File Submission Specifications for further details.

Why does PMC require the full text of every article in XML? Why not accept just a PDF or HTML file?

We believe that XML currently is the most effective archival format for the textual portion of a journal article. It essentially is software- and hardware-independent, and therefore adapts easily to changes in technology. XML lets you preserve the structure and meaning of an article in a relatively simple and human readable form.

With a well-documented DTD, which serves as the "code book" for a piece of XML, you have something that people will still be able to decipher and use several generations from now, regardless of changes in technology. This characteristic lends XML to being converted to a more advanced text recording format in the future. XML tagging also makes it easier to automatically parse the content of an article, which can help with more focused searching and with linking the article to related content in other databases, e.g., links to factual reference data.

PMC has its own DTD based on the JATS Journal Article Tag Suite (JATS), which was created specifically for archiving digital journal content. See Does PMC have its own DTD? below.

Does PMC have its own DTD? Must data be submitted in this format?

NLM supports the Journal Article Tag Suite (JATS) that any journal may use to submit its data. The JATS DTD is well documented and is increasingly being adopted by other organizations in the field. PMC creates the HTML page for an article dynamically from the archival XML every time that a user retrieves an article. In that respect, every request confirms that the archival copy is still functional. PMC will also accept data in other full-text article DTDs that are widely used in life sciences journal publishing.

Must a journal include PDF versions of its articles in PMC?

If a journal has PDF versions of its articles, NLM asks that they be deposited in the archive. A journal is not required to create PDFs solely for PMC if it does not have them otherwise.

How can a publisher be sure that PMC will not alter the substance or meaning of submitted content?

PMC does not change the content of submitted articles in any way. Experience to date suggests that participation in PMC may actually improve the quality of a journal's digital archival record, because PMC does an independent check of the accuracy of the XML/SGML and related files. The initial setup for a journal in PMC involves a thorough automated and manual review of the journal's content to ensure the accuracy of the material. The publisher is also asked to review its content in PMC before a journal is released to the public initially.

PMC's checking includes a comparison of the content in PMC to that at the journal's own web site and/or to the PDF version of the journal's articles. When discrepancies are found, the publisher is asked to provide corrected files to PMC, precisely because PMC does not want to make any changes to the publisher's content itself. Content deposited after the journal is live in PMC is verified and corrected in a similar manner.

PMC's approach to archiving adds a further, and significant, level of quality assurance. Every time a user asks to see an article in PMC, the online (HTML) view of that article is created on the spot, directly from a copy of the archival files — XML, image files, etc. PMC does not maintain a static html display of an article. Thus, every person who requests and reads an article in PMC is verifying the integrity of the archived files.

How much work is required of a publisher to prepare journal content for PMC?

Many publishers already create XML versions of their articles as part of the journal production process. These journals must only arrange to transmit their XML files to PMC together with associated image files and, as applicable, PDFs and supplementary data files. Some additional work may be needed, initially, to refine the journal's process for creating XML, if the submitted data does not satisfy PMC's technical standards..

A publisher that does not currently produce XML versions of its articles would have to add this process to its production stream or contract with a vendor to create XML from the article source files.

What is the cost of participating in PMC?

There is no charge to publishers for including journal content in the PMC archive. A publisher is responsible only for any costs incurred in creating files that meet PMC's technical standards and transmitting them to PMC.

What do publishers gain by depositing their content in PMC?

Publishers receive the benefit of a permanent and freely accessible archive, managed by the National Library of Medicine, at almost no cost— merely what it costs to provide PMC a copy of the material. Every publisher can request from NLM and receive, free, a copy of their archived content at any time.

NLM's experience in digital journal archiving is evident in its development of the publicly available Journal Article Tag Suite. The DTD has been endorsed by the U.S. Library of Congress and the British Library as a standard for digital journal archiving. It has also been officially adopted as an American National Standards Institute (ANSI)/ National Information Standards Organization (NISO) standard.

Participation in PMC usually improves the overall level of quality of a journal's archival files, as explained in the answer to a related FAQ. The journal also benefits from the integration of its full text with PubMed and the numerous other bibliographic and factual databases in NCBI's Entrez system, and the increased exposure that this brings.

Why is PMC needed when many publishers already make their journals freely available on the web within a year of publication?

PMC exists for two reasons, both of which arise from NLM's Congressional mandate: 1) to permanently preserve digital journal literature in the life sciences, and 2) to improve access to biomedical information for health professionals, researchers and the public.

PMC gathers the content from its diverse journal sources into a single repository, where it is stored in a uniform and well defined structured format, the NLM Journal Archiving and Interchange XML DTD. At the same time that PMC clearly maintains the identity of each journal, it also displays articles in a uniform style for users.

PMC's common archival format makes it easier to work with the material and extend its utility in efficient ways, using computational techniques. It allows greater integration of the literature with related resources, such as the variety of databases available in NCBI's Entrez system. New features can be applied consistently across the collection in a scalable manner. Once a technique has been developed, there is little extra cost to handle increased amounts of content. Experience has shown that this integration of information resources leads users to new knowledge and stimulates scientific discovery.

Why does PMC require the deposit of complete articles, rather than linking to a journal site for full text?

NLM's journal abstract database, PubMed, already has links to full text at the online sites of thousands of journals that participate in the freely available LinkOut service. One of the primary goals of PMC is the creation of a digital archive of journal literature which, by definition, means the full text must be deposited in PMC. See the answers to the preceding questions to learn about some of the benefits of depositing content in PMC.

What kinds of links does PMC provide from its site to a journal site?

PMC displays a journal banner — a graphic supplied by the journal — for all full participation journals. Although the banner may not include commercial advertising, it can link to a page at the journal site. Some banners even provide a link from the full text of an article in PMC to the corresponding article at the journal site. See PLoS Biology, for example.

A journal also has the option to include a link from PMC's general PMC Copyright Notice to a more specific statement of terms and conditions of use posted on the journal site.

How are journal citations submitted to PubMed?

Details are available on the PMC Policies page in the section titled "PubMed Submissions".

What kinds of usage statistics does PMC provide to participating journals?

Each publisher has password-controlled access to a web site that has usage reports for that publisher's journal(s). The reports, updated daily and aggregated by month, include counts of available articles, total access by type of page (e.g., full-text HTML or PDF); unique IP addresses; and most frequently retrieved or cited articles. Any report may be downloaded as a CSV or XML file.

Monthly use at an individual article level is also available in CSV and XML form.

NLM's privacy policy does not allow the identification of use made by specific individuals, organizations or IP addresses. Therefore, the usage reports do not include this level of data.

Participating publishers should contact their PMC journal manager for assistance with accessing the statistics website.

What is PMC’s policy on accepting articles that are Ahead-of-Print?

Ahead of Print (AOP) articles are articles that are released online before their final, published versions appear in their corresponding issue, online or in print. PMC generally does not accept AOP articles. An exception may be made for an article that needs to be available in PMC immediately in order to satisfy a funding agency’s policy.

What is PMC’s policy on retractions?

PMC will not remove articles from its archive. For information on our retractions policy, see "Retractions" on the PMC Policies page.

How can I, as a publisher, ensure that my journal title is on the NIH Public Access Policy Journal list?

In order for a journal title to appear on the NIH Public Access Policy Journal list, a publisher must first have a formal PMC participation agreement stipulating that you will deposit either the complete contents of a journal or, at a minimum, all the NIH-funded articles that are included in the journal to be made available within 12 months of publication. Once the journal evaluation is complete and content has been successfully submitted and processed, your journal title will then show up on the NIH Public Access Policy Journal list.

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Last updated: Wed, 22 July 2015