On August 22, 2004, the USPTO upgraded its ePave server from version 5.1 to version 5.1d. The consequence of this is that would-be e-filers in the US Patent Office must use ePave 5.1d instead of ePave 5.1. ePave 5.1d will not accept Annex-F-compliant patent applications. Instead, it will only accept patent applications in a proprietary format prepared using EFS-ABX 1.1. For this reason, anyone who wishes to e-file a US patent application must download, install, and use ePave 5.1d and EFS-ABX 1.1. This web page is intended to support users of ePave 5.1d and EFS-ABX 1.1.
On September 28, 2004, the USPTO hosted a Patent Electronic Filing Forum. You can see the roster of attendees, a report by Carl Oppedahl, and USPTO's report. Many of the views compiled in this Forum had been previously identified in a report of a survey of EFS list members carried out a year ago.(Prior to August 22, 2004, there were many ways to e-file US patent applications. You can see the old EFS support page which by now is of only historical interest.)
The single most important thing you can do is to join the EFS listserver. This permits you to learn of developments regarding EFS and you can post questions and answers about EFS.
Frequently asked questions about EFS
This page is http://www.patents.com/efs , revised at least as recently as August 2004.