What is XFDF?
XFDF, short for "XML Forms Data Format," serves as the XML counterpart to FDF (Forms Data Format). It is defined by ISO 19444-1:2019, a standard titled "Document management - XML Forms Data Format — Part 1: Use of ISO 32000-2 (XFDF 3.0).
XFDF, a XML-based file format, is used to store form data and annotations separately from the actual PDF document. XFDF files can be used to import or export data and annotations for PDF forms. They allow for easy sharing and processing of form-related information, making it simpler to manage and exchange data between different systems and applications.