PubMed Central and the NLM Journal Archiving Vocabulary Jeffrey Beck National Center for Biotechnology Information National Library of Medicine PubMed Central (PMC) is the National Library of Medicine's digital archive of life sciences journal literature. PMC is an XML-based system. We accept content in SGML or XML and convert it to a common XML format that is loaded into the archive. As the early mission for PMC grew from simple online access to access and preservation, our requirements for a common XML format also changed. Last year, NCBI released two XML DTDs based on the NLM Archiving and Interchange Vocabulary. The DTDs were created after collaboration between the Harvard University E-Journal Archiving Project and NCBI. They may be used as is, or the vocabulary can be used to construct other models. These DTDs and the vocabulary are in the public domain and have already been accepted widely. We have started to digitize back issues of PMC journals that are not already available in electronic form to create a complete digital archive of the journals that are in PubMed Central.   Web Link: http://dtd.nlm.nih.gov/ Presentation: PubMed Central and the NLM Journal Archiving Vocabulary (PPT)