PDF/A-1b is suitable for archiving PDF 1.3 or PDF 1.4 files whose content structure ...

PDF/A-2a is suitable for archiving PDF files up to version 1.7 whose content structu...

PDF/A-2b is suitable for archiving PDF files up to version 1.7 whose content structu...

PDF/A-2u is suitable for archiving PDF files up to version 1.7 whose content structu...

PDF/A-3a is similar to PDF/A-2a but allows embedding of non-PDF/A files

PDF/A-3b is similar to PDF/A-2b but allows embedding of non-PDF/A files

PDF/A-3u is similar to PDF/A-2u but allows embedding of non-PDF/A files

PDF/AEX

PDF/E

PDF/E or PDF/X