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Glossary

Standards, defined

A precise reference for the PDF, digital signature, e-invoice, and integration terms used across NextPDF.

Reference

Terms

PDF 2.0 ISO 32000-2
The current generation of the PDF format. NextPDF is built around its object model for document structure, digital signatures, archival profiles, and colour management.
PDF/UA-2 ISO 14289-2
The accessibility profile for PDF 2.0. It covers logical structure, document language, reading order, and figure alternative text. Meaningful content remains an editorial responsibility.
PDF/A-3 ISO 19005-3
An archival profile that permits embedded files. ZUGFeRD and Factur-X use PDF/A-3 as a carrier for structured XML and a human-readable invoice.
PDF/A-4 ISO 19005-4
The PDF 2.0-based archival profile for long-term preservation. NextPDF Enterprise targets PDF/A-4 for standalone archival output.
PAdES ETSI EN 319 142-1
PDF Advanced Electronic Signatures. The ETSI profile family defines four baseline levels for digital signatures in PDF: PAdES B-B/B-T/B-LT/B-LTA.
PAdES B-B (Baseline) ETSI EN 319 142-1
The baseline level. It embeds the digital signature and signer certificate in the PDF. NextPDF Core provides PAdES B-B.
PAdES B-T (Timestamped) RFC 3161
Adds an RFC 3161 timestamp token for the existing digital signature. NextPDF Pro provides PAdES B-T.
PAdES B-LT (Long-term) ETSI EN 319 142-1
Adds validation material in the DSS, including certificates and revocation data. NextPDF Enterprise provides PAdES B-LT.
PAdES B-LTA (Long-term archival) ETSI EN 319 142-1
Adds document timestamps over the signature and its validation material to support archival validation. NextPDF Enterprise provides PAdES B-LTA.
CMS SignedData RFC 5652
The Cryptographic Message Syntax structure that carries a digital signature and related certificate information. PAdES embeds this structure in the PDF signature container.
ByteRange ISO 32000-2
The PDF entry that identifies the byte ranges covered by a digital signature. The signature value occupies the excluded range.
DSS (Document Security Store) ISO 32000-2
The PDF structure used to hold certificate and revocation information for validation. PAdES B-LT/B-LTA require this validation material.
RFC 3161 timestamp RFC 3161
A timestamp token issued by a Time-Stamping Authority for data presented to it. NextPDF Pro uses it for PAdES B-T.
EN 16931 EN 16931-1
The European semantic model for the core elements of an electronic invoice. NextPDF Enterprise targets it for structured invoice data in hybrid PDFs.
ZUGFeRD and Factur-X EN 16931 · PDF/A-3
Hybrid e-invoice formats that pair a human-readable PDF/A-3 document with embedded structured XML. Their profiles include mappings to the EN 16931 semantic model.
ICC v4 colour ISO 15076-1
Version 4 profiles from the International Color Consortium. They describe colour transformations for colour-managed output across devices and workflows.
MCP (Model Context Protocol)
A protocol for exposing tools to AI systems. NextPDF Connect offers MCP alongside REST and gRPC for its typed PDF operations.
HSM / PKCS#11
A Hardware Security Module and its PKCS#11 interface. NextPDF Enterprise can route signing through a configured module. Key residency follows the module and key attributes in your deployment.

Put the terms in context

Find edition details and deployment answers in the supporting reference pages.