The Register of Copyrights is nowhere defined in the article, but I imagine that it's the person at the Library of Congress' Copyright Office who stamps the "Approved" letter on your application. It's the office to which you send your $45 to get a copyright certificate. http://www.copyright.gov/register/literary.html (Which applies to software as well as books).

So, either it's a department head appointed by the president, or it's someone who's probably bored of reading copyright applications and enjoys the smell of rubber stamps. Either way, there's not a lot of trust being inspired here.