PDF/A (Portable Document Format Archivable) is a variant of the regular PDF format and was specially developed for the long-term archiving of documents. The basic idea here is that a PDF/A-compliant document contains all the information itself that is required for its faithful representation. Thus, a document that uses an external image or font would not be PDF/A compliant because it accesses resources that must be installed on the displaying computer. Fonts in particular pose a problem here because the standard set of installed fonts differs from device to device and, above all, may not be stable over long periods of time. In the worst case, the text of a document is no longer readable after years, even though the document was displayed error-free on all common systems at the time of creation.

Since the beginning of 2021, a "pdfa" option has been available in the LaTeX styles from Dagstuhl Publishing, which at least ensures that the PDF output is "PDF/A-ready". This means that reworking is usually only necessary for embedded PDF graphics (created with third-party software) or if special LaTeX packages have been used. Such cases are resolved by Dagstuhl Publishing in manual typesetting. The validation is based on the PDF/A 3b standard.

The pdfa option must be set as an option of the \documentclass in LaTeX. Using the LIPIcs style as an example, this looks like this:
\documentclass[pdfa]{lipics-v2021}
By the way, this option also ensures that the basic metadata (such as title, authors, keywords) are already stored in the PDF document.

All papers published in the LIPIcs and OASIcs series since the beginning of 2021 have been completed with the ninth version of the LaTeX style and published as PDF/A-compliant documents.

If you have any questions about PDF/A, please contact submission@dagstuhl.de.