Federal courts are advising practitioners that PDF/A will now be the required format for electronic filings in the CM/ECF system.  PDF/A is the standard for long-term archival storage of PDFs.  For a full explanation of PDF/A, see Rick Borstein’s blog post: Federal Courts Moving to Requiring PDF/A for Filings.  Rick’s blog is a terrific resource for anyone in the legal community who wants to learn how to use Acrobat to it’s fullest.