| Feature | Standard PDF | PDF/A (Archival) | | :--- | :--- | :--- | | | May use system fonts | Must embed all fonts | | Transparency | Supported | Must be flattened | | Color Space | RGB (screen) | RGB, CMYK, or Grayscale only | | JavaScript | Allowed | Forbidden | | Metadata | Optional | Required (XMP) | Why You Cannot Use HTML's <!DOCTYPE> Logic A common mistake is assuming a PDF has a plain-text doctype string. It does not. If you open a .pdf in a text editor, you will see binary data mixed with obj and stream tags. To find the "doctype," look for the XMP metadata :
In the world of digital documents, a standard PDF is like a sticky note: useful, but not guaranteed to last. If you have ever opened a decade-old PDF only to find missing fonts, broken images, or corrupted data, you have witnessed the failure of a standard "doctype." doctype pdf
The answer is . It strips out JavaScript, video, audio, and external dependencies. It forces every font and image into the file. It is the legal standard for court filings (US federal courts), library archives (Internet Archive), and engineering blueprints (ISO standards). | Feature | Standard PDF | PDF/A (Archival)