The National Archives and Records Administration, the US federal agency charged with retention of government records, has just issued NARA Bulletin 2014-004, the new Transfer Guidance for federal agencies.

Last updated in 2003, this Bulletin "specifies which file formats are acceptable when transferring permanent electronic records to NARA." The guidance applies to all federal records.

This iteration of NARA's Transfer Guidance incorporates a number of changes specific to distinct categories of documents.

For CAD

• PDF/E and PRC are "acceptable"

For Scanned Text

• PDF/A-1 is "preferred"
• PDF/A-2 is "acceptable"

For Digital Posters

• PDF/A-1 is "preferred"

For Presentation Formats

• PDF/A-1 is "preferred"
• PDF/A-2 is "acceptable"

For Textual Data Formats

• PDF/A-1 and PDF/A-2 are "preferred"
• PDF 1.7 and PDF 1.0 - 1.6 are "acceptable" 

See NARA's 2014-004 Transfer Guidance, Appendix A for more details. PDF Association Vice Chairman Duff Johnson has written an unofficial summary of the changes as they pertain to PDF.