From Just Solve the File Format Problem
File Formats | > | Electronic File Formats | > | Document | > |
PDF, portable document format, based on PostScript and originally from Adobe, has many subsets.
As well as the 'full function' ISO 32000-1:2008 (or PDF 1.7) there is also PDF/X, PDF/A, PDF/E, PDF/VT and PDF/UA all of which are ISO specifications.