What Is a MIME Type? In PDF/A, MIME types (also called media types ) are used to identify the format of embedded files and associated files. They are stored in the embedded file stream's /Subtype entry and are required for PDF/A compliance when attachments are present. Examples include: File Type MIME Type PDF application/pdf XML application/xml TXT text/plain CSV text/csv JPEG image/jpeg PNG image/png TIFF image/tiff ZIP application/zip In PDF/A documents, MIME types become important when files are embedded as Associated Files (AF) or traditional file attachments. Why MIME Types Matter in PDF/A PDF/A is designed for long-term archiving . When a file is embedded, future software must be able to identify: What the embedded file contains How it should be processed Which application can open it The MIME type provides this information. Without a correct MIME type: Validation may fail Archival systems may misinterpret the file PDF/A compliance can be lost Common ...
What Is AFRelationship? AFRelationship (Associated File Relationship) is a metadata property used in PDFs to describe the relationship between a PDF document and an embedded file (attachment). It was introduced with the Associated Files (AF) mechanism in the PDF specification and is heavily used in modern PDF/A standards. AFRelationship tells software and archives: Why is this file attached to the PDF? Without AFRelationship, an attachment may be considered invalid for PDF/A compliance. Why AFRelationship Matters When a file is embedded in a PDF/A document: The attachment must have a MIME type. The attachment should have a meaningful AFRelationship value. PDF validators use AFRelationship to verify compliance. Examples: Attachment AFRelationship Original XML invoice Source Spreadsheet used to generate report Data Alternative representation of content Alternative Supple...