This product supports PDF versions 1.0 to 2.0; this topic summarizes which features are supported in each version. Features not mentioned here are supported in all versions. PDF files created by the product can be from versions 1.3 to 2.0 or PDF/A (based on version 1.4) or USPTO compliant (based on version 1.4 with all fonts embedded, high quality and security protection disallowed). For more compliance information visit the US Patent and Trademarks Office website at www.uspto.gov.
Encryption
40-bit RC4 – Supported in PDF version 1.1 and above (security revision 2)
128-bit RC4 - Supported in PDF version 1.4 and above (security revision 3)
128-bit AES – Supported in PDF version 1.6 and above (security revision 3)
256-bit AES – Supported in PDF version 1.7 and above (security revision 3)
Document permissions
The available set of document permissions depend on the security revision number (defined in the PDF standard). Two security revisions are used: 2 and 3.
Security revision 2 (RC4-40 encryption) allows the document creator to restrict the following operations:
Modifying the document contents
Copying text and graphics from the document
Adding or modifying text annotations and interactive form fields
Printing the document
Security revision 3 (RC4-128, RC4-128 or RC-256 encryption) adds the following operations to the repertoire the document creator can control:
Form fill-in and sign document
Text inspection for accessibility
Document assembly including insertion, deletion of pages and creation of bookmarks and thumbnails
Allow only printing that does not allow perfect digital copies, but which may also result in degradation of output quality
Metadata
Metadata fields are supported in PDF version 1.1 and above.
PDF standards
PDF/A: Supported in PDF version 1.4 only.
PDF/X: Supported in PDF version 1.3 and above.
PDF/E: Supported in PDF version 1.6 and above.
PDF/UA: Supported in PDF 1.7 and above.
Linearized PDF: Supported in PDF version 1.2 and above.
Note: If the PDF/A option is turned on, all controls in the Password Security panel are disabled.
PDF/A is a standard designed to be usable in wide range of applications and operating systems, as much possible, and also withstand future technological developments. PDF/A is based on PDF version 1.4, so earlier PDF products can handle them. It excludes elements like JavaScript, which may not be correctly interpreted in some environments. It requires certain items, such as adequate tagging, good accessibility, and suitable metadata. The program can handle all PDF/A subtypes, and its Advanced version provides a PDF compliance checker and an Accessibility checker.
PDF/X is a middle-state format for exchange during prepress activities. Serves as a final-state digital format to the extent, that it is used for online proofing prior to printing. PDF/X has a series of printing related requirements which do not apply to standard PDF files. For example, fonts must be embedded, images need to use CMYK or spot colors in most of the PDF/X subformats.
PDF/E is a document format used in engineering, mostly when documenting geospatial, constructional and manufacturing workflow. The specification supports interactive media, including animation and 3D.
PDF/UA (resembling to Universal Accessibility) constrained form of PDF 1.7 intended to ensure accessibility and support for assistive technology used by people with disability.
Linearized PDF is optimized for faster web display, so the first page displays quickly while other pages are still being processed.
Compression methods
MRC compression is supported in PDF 1.3 and above, for image-only PDF files.
When a PDF contains many photos, use of JPEG2000 can reduce file size by 50% or more, compared to earlier compression methods, without visibly losing quality.