PDFA2b

PDFA2b is one of the conformance levels defined in the ISO 19005‑2 standard, which specifies requirements for the long‑term preservation of electronic documents in Portable Document Format (PDF). The standard was published in 2011 and extends the original ISO 19005‑1 (PDF/A‑1) by adding support for new PDF features introduced in later PDF versions while maintaining backward compatibility.

The “b” in PDF/A‑2b denotes a level of compliance that requires the document to be visually compliant with PDF/A‑1, meaning that all visible elements render consistently across compliant readers. In contrast, PDF/A‑2a demands full logical accessibility, and PDF/A‑2u requires Unicode text extraction. PDF/A‑2b therefore offers a balance between machine preservation and user readability without imposing the more strict markup and coding requirements of levels a or u.

PDF/A‑2 supports newer features such as external object references, derivatives, improved color management, and encryption. It allows the use of 16‑bit color and higher‑resolution imaging. However, it disallows font embedding unless the fonts are subset or embedded in a specific format, and it prohibits JavaScript. PDF documents must still contain an embedded, searchable text layer for visual fidelity.

Many software packages, including Adobe Acrobat, Ghostscript, and open‑source PDF libraries, provide tools to create, validate, and convert documents to PDF/A‑2b. The format is widely adopted in archival, legal, and government contexts where documents must be preserved over decades or centuries.