PDF/A-1a is with conformance level A (for "accessibility"), and must adhere to all of the requirements of the PDF Reference as modified by the ISO 19005 specification. 

It requires structural and semantic properties to be preserved. Level 1a uses “Tagged PDF” and Unicode character maps to preserve the document's logical structure and content text stream in natural reading order. 

The following features are used:
- Language specification
- Hierarchical document structure
- Tagged text spans and descriptive text for images and symbols
- Character mappings to Unicode

The purpose is to improve accessibility and make the content accessible for screen readers.

For complienace level PDF/A-2a please follow: PdfProcessing: Add support for PDF/A-2a compliance level.

The currently supported compliance levels can be found in the How to Comply with PDF/A Standard article.

Currently the DocumentInfo property is for export purposes only and meta information about documents is stripped when importing.

According to the PDF specification (ISO 32000), the document info dictionary (often called "metadata" or "Info" dictionary) can include the following standard fields:

• Title: The document’s title.
• Author: The name of the person who created the document.
• Subject: The subject of the document.
• Keywords: Keywords associated with the document.
• Creator: The application that created the original document.
• Producer: The application that converted the document to PDF.
• CreationDate: The date and time the document was created.
• ModDate: The date and time the document was last modified.
• Trapped: Indicates whether the document has been trapped (a printing term).

These fields are stored in the PDF’s Info dictionary and are used by PDF viewers for display, search, and indexing.

 

Purpose: Long-term archiving of electronic documents with full semantic structure.

• "A" for Archiving

• Level "1a" ensures:

  • Tagged PDF (with proper logical structure and reading order)

  • Unicode text for proper text extraction and searchability

  • Embedded fonts (for consistent rendering)

• Restrictions:

  • No audio/video

  • No encryption

  • No JavaScript

  • No external content (everything must be self-contained)

• Based on: PDF 1.4 (Acrobat 5)

Part 3 of the standard, published on October 15, 2012, differs from PDF/A-2 in only one regard: it allows embedding of arbitrary file formats (such as XML, CSV, CAD, word-processing documents, spreadsheet documents, and others) into PDF/A conforming documents.

PDF/UA (PDF/Universal Accessibility) is the informal name for ISO 14289, the International Standard for accessible PDF technology.

Error message:

System.InvalidCastException: 'Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfArray' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.Functions.FunctionObject'.'

The PDF/A-1 standard uses the PDF Reference 1.4 and specifies two levels of compliance:

- PDF/A-1b - Its goal is to ensure reliable reproduction of the visual appearance of the document.

- PDF/A-1a - Its objective is to ensure that documents content can be searched and re-purposed. This compliance level has some additional requirements:

• Document structure must be included.
• Tagged PDF.
• Unicode character maps
• Language specification.

Since the PdfProcessing and its PdfFormatProvider is compliant with the PDF Reference 1.7. , the produced documents are created with this version as well: 

Implement Viewer related properties in PdfProcessing in order to enable the users to set PrintScaling, Duplex, and other properties which are written in the Pdf Format specification as Interactive Features. 

ViewerPreferences are written a document's catalog. Check p.577 from pdf reference format specification, version 1.7

It would be great if the SkiaImageExportSettings offer a DocumentUnhandledException event allowing the developer to handle specific errors when exporting to image formats.

This would be an essential improvement in the existing Exception handling mechanism and would enable exporting PDF documents to images even though some parts of the image may not be completely supported: https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/features/handling-document-exceptions 

When applying MultipleSubstFormat1, an exception is thrown: "NullReferenceException: 'Object reference not set to an instance of an object.'"

The issue is not reproducible in Q1 2025 (2025.1.205).

In Q2 2025 we introduced the MarkedContent in a RadFixedDocument.

This error happens when importing a document.

Handle documents with mismatched font Subtype and FontFile type when exporting PDF to image with SkiaImageFormatProvider.

The StokeAlphaContant is not handled correctly when applied on a TextFragment:

Wrong clipping order when exporting a document with MarkedContent leads to a missing content.

The standard fonts listed at http://docs.telerik.com/devtools/wpf/controls/radpdfprocessing/concepts/fonts#standard-fonts cannot be embedded in a document. Using one of them prevents the document from complying with PDF/A standard.

Wrong font loading when FontFile2 is CFF (Compact Font Format).

Implement functionality to support scenario when a document which already has a signature to be signed again or add two or more signatures.

ArgumentOutOfRangeException is thrown when creating a CapPathRound for an SVG element.

Exporting a specific PDF file generates large amounts of ExtGState entries, which results in large file sizes.