My post assumed that the Register of Copyrights is an inferior officer. The Supreme Court has found that “any appointee exercising significant authority pursuant to the laws of the United States is an `Officer of the United States,’ and must, therefore, be appointed in the manner prescribed by 2, cl. 2, of [Art. II].” Buckley v. Valeo, at 126.

This creates a three-pronged structure: department heads (who have the power to appoint inferior officers); inferior officers (who must be appointed in a manner consistent with the Appointments Clause); and lesser functionaries, sometimes referred to as employees (who don’t have to be selected in compliance with the Appointments Clause).

I think it’s relatively safe to assume that the Register is an inferior officer, given the extensive role that the position plays in policy formation. It’s not a position relegated to “ministerial tasks.”

I suppose you could argue that the registrations are valid because the reviewers at the Copyright Office are employees, but there are problems with this line of attack. Every Certificate of Registration contains a signature from the Register asserting validity. [Edit: This is statutory. Under 17 U.S.C. 410, it is the Register who determines whether applications consist of copyrightable subject matter, registers works and issues certificates.]

Here’s a sample: http://books.loudorangecat.com/images/copyright.jpg.