PDF format specifics
PDF stands for Portable Document Format. With its common and almost universal use, it is often referred to as "digital paper". It is widely used for different kinds of documents: reports, papers, legal documents, contracts, agreements, e-books, manuals, surveys, etc. Various programs, like Adobe Acrobat Reader, internet browsers, preview applications, online PDF viewers, and others support PDF format documents.
More and more dynamic properties have been added over time during PDF development. Interactive forms, support for JavaScript actions, annotations, etc., expanded its application area, especially when it comes to complex workflows or presentation of information.
Therefore, it goes beyond just being a simple equivalent of paper in digital space.
Signing PDF format document. What to do before signing.
Always check twice
PDF being by far most often used document format together with electronic signatures, it is essential to assess all sides of this comprehensive format properly before signing anything.
If you are signing PDF format document, please ensure that the PDF previewer of your choice displays the original document content. If you are not aware of, for example, the JavaScript being executed by the previewer, you are risking signing the content you are not familiar with.
Note: In Dokobit by Signicat portal, the JavaScript snippet is disclosed, and our previewer prevents the execution of the JavaScript. Thus, the original content is detected.
If any doubt, use PDF/A format
PDF/A — the ISO standard format intended for long-term preservation of the document's content. The requirements for PDF/A do not allow the documents to include any dynamic content: interactive forms, JavaScript, audio, video, external fonts, or encryption. This ensures that viewing the content of such a document does not vary depending on the program used for PDF/A preview: the same content will be shown in all programs, whether they prevent the execution of JavaScript or not.
You can check more on PDF/A standard here: PDF/A in a Nutshell, or here: PDF/A FAQ.
For this reason, you can always choose to sign PDF/A instead of PDF format document. To create such a document, you will need to specifically choose and select this format before saving it in a program of your choice. Please note that some programs may only offer the functionality of saving documents in PDF/A format with a paid subscription plan.