(a) When a request is made in person, or when records are made available in person following a request made by mail, the department may require appropriate identification.

(b) When a request is made by mail, the department may require verification of a signature or inclusion of an identifier generally known only by a data subject, or similar appropriate identification.

(c) Proof of identity shall not be required regarding a request for a record accessible to the public pursuant to article 6 of the Public Officers Law.