Many years ago, the Judiciary embraced the PDF standard for documents filed in CM/ECF. Since it was first adopted, the PDF standard has evolved to include new features, some of which have raised concerns about the security and long-term archival storage of the documents. The newer PDF/A standard addresses those concerns. Standard word processing software is now capable of producing PDF/A documents, so it is both possible and desirable for the Judiciary to move towards the PDF/A standard.
PDF/A documents can already be accepted by current versions of CM/ECF. Upcoming releases of CM/ECF will allow courts to require documents to be in PDF/A format; the applications also give each court a choice in how to gradually transition to that goal.