What is a Fragment Identifier?

Fragment Identifier is a feature defined in Annex O of ISO 32000-2 that allows precise content anchoring and display control within linked PDF files using URLs. These identifiers follow the # symbol in a URL and control what content is shown.

For example, you can open a specific PDF page by adding #page=n (where n starts from 1) to the URL: https://www.pdfa.org/wp-content/uploads/2013/05/PDFA_in_a_Nutshell_211.pdf#page=5 opens the 5th page of the PDF.