PDF Knowledge Base
The following articles on PDF topics are currently available:
PDF 2.0
Overview of new features in PDF 2.0 according to ISO 32000-2:2020
PDF Password Security
Encryption methods for securing PDF documents with user and master password
PDF Certificate Security
Encryption methods for securing PDF documents with public-key certificates
PDF/A
PDF for Archiving according to ISO 19005
PDF/UA
PDF/UA for Universal Accessibility according to ISO 14289
PDF/VT
PDF/VT for variable data printing and transactional printing according to ISO 16612
PDF/X Output Intents
PDF/X Output Intents for describing printer process and paper type
ZUGFeRD and Factur-X
Standards for exchanging invoices as PDF
XMP
Metadata format for use in XMP and other document formats