What is the Departmental Register and Secret Register for patent assignments?

The USPTO maintains two special registers for recording certain government interests in patents and patent applications, as outlined in 37 CFR 3.58:

1. Departmental Register: This register records governmental interests required by Executive Order 9424. It is not open to public inspection but can be examined by authorized government representatives. However, governmental interests recorded on this register are available for public inspection as provided in 37 CFR 1.12.
2. Secret Register: This register is used to record governmental interests that require secrecy. Documents are placed on this register at the request of the submitting department or agency. Access to this register is highly restricted and requires written authority from the head of the department or agency that submitted the document, as well as approval from the USPTO Director.

These registers ensure that certain sensitive government interests in patents can be recorded while maintaining appropriate levels of confidentiality or secrecy.