Further development and optimization of the PDF format
The PDF format is considered an interoperable file format that stands out due to its reliable and consistent behavior. In addition, the format is continuously updated and improved. This also includes regular reporting of errors and issues.
This helps everyone in the PDF ecosystem, from developers to end users. Reporting issues, working on solutions, and publishing results are all essential for ensuring PDF interoperability.
Corrections by the PDF Technical Working Group of the PDF Association
A key contributor here is the PDF Technical Working Group of the PDF Association, which has compiled extensive knowledge on PDF-related issues. Corrections and clarifications range from typographical and formatting errors to language clarifications and the elimination of incorrect cross-references.
PDF issues also include larger topics, such as missing (previously undocumented) keys in dictionaries, changes to optional or required key status, corrections to allowed key values, and the addition of missing annexes. These changes are highly relevant for PDF developers.
Each solution links to one or more GitHub issue numbers so developers can trace technical discussions. The repository pdf-issues is therefore a key source for technical PDF topics.
Not only relevant for the PDF 2.0 specification
Although resolved issues are shown as marked changes to the latest PDF 2.0 specification (ISO 32000-2:2020), many corrections are also highly relevant for earlier PDF specifications.
PDF is backward compatible, and many clauses from older specifications were retained or only slightly adjusted. Clause numbering remains largely consistent between PDF 1.7 (ISO 32000-1:2008) and PDF 2.0 (ISO 32000-2:2020). This makes it easier for developers to identify corrections and map them to previous specifications.
GitHub repository pdf-issues
The PDF Technical Working Group (TWG) of the PDF Association meets regularly to review reported issues and approve proposed solutions. PDF developers should keep an eye on the pdf-issues repository and actively join discussions on relevant topics.
If you are involved in PDF development, this repository should be part of your standard workflow. The PDF Association clearly states: every bug report is welcome, no matter how small.
https://github.com/pdf-association/pdf-issues
Revision of PDF Forms technology
One example of detailed improvements is the ongoing revision of PDF Forms technology. The PDF Forms Technical Working Group is developing proposals to address issues identified over the years.
A central aspect is the shift from a scripting approach without fully documented behavior to a declarative model for business logic and form rules. This affects not only calculations, but also formatting and validation.
Another important goal is to align PDF form capabilities more closely with modern web technologies so that conversion from HTML to PDF and from PDF to HTML can be as lossless as possible. Support for technologies such as JSON for data modeling and exchange is also being expanded. Accessibility improvements for field labels and field groups are another focus.