More about PDF Topics

PDF Security - more about security for PDF documents

Encryption: encryption algorithms, key length, and passwords

Permissions: various permission settings for PDF documents

Recommendations: security recommendations for PDF data

PDF/A - more about the longterm archiving standard

Validation Report: The Bavaria report tests the validation quality of PDF/A validating software.

XMP - more about metadata in PDF

XMP Panels: How to display and edit XMP metadata.

XMP in PDF/A: Describes how XMP has to be used in PDF/A documents.

XMP Validation: Ways to ensure that XMP conforms to the XMP specification,

Free XMP Validator:  XMP validator for PDF/A-1 (powered by PDFlib)