From the U.S. Copyright Office:
The U.S. Copyright Office today announces the posting of redlines comparing the current version of Compendium of Copyright Office Practices (Third), which was released December 22, 2014, and the public draft of Compendium (Third), which was released June 1, 2017.
The redlines are available on the revision history portion of the Compendium webpage.
They are intended to assist members of the public in understanding the amendments and revisions contained in the public draft.
The Office has extended the deadline to provide comments until July 30, 2017. Comments may be submitted on the Office’s website.