49 C.F.R. § 512.16 – Class determinations.

(a) The Chief Counsel may issue class determinations of categories of information to be entitled to confidential treatment if the Chief Counsel determines that one or more characteristics common to each item of information in that class, will, in most cases, result in identical treatment, and further that it is appropriate to treat all such items as a class for one or more purposes under this part. Once a class determination is made, the Chief Counsel will publish the new class determination in the Federal Register.
(b) The Chief Counsel may amend, modify, or terminate any class determination established under this section. These changes will be published in the Federal Register.
(c) Class determinations made by the Chief Counsel are listed in Appendices B and C to this Part.
(d) A class determination may state that all of the information in the class:
1. (1) Is or is not governed by a particular section of this part or by a particular set of substantive criteria of this part;
2. (2) Satisfies one or more of the applicable substantive criteria; or
3. (3) Satisfies one or more of the substantive criteria, but only for a certain period of time.