Display Formats: XML Format and PMID List
XML (eXtensible Markup Language) is another tagged format. XML is generally used for displaying and manipulating data in software applications. However, we recommend that you use the E-Utilities for downloading sets of PubMed records for manipulation and display in other systems.
Use PMID List to create a plain text list of PubMed identifiers (PMIDs) that can be used to efficiently retrieve batches of PubMed records in the future. See more about using PMIDs.