5 CFR 294.301: Policy and interpretations.

(a) Statements of Office policy and interpretations of the laws and regulations administered by the Office which the Office has adopted, whether or not published in the Federal Register, are available to the public.

(b) Generally, memoranda, correspondence, opinions, data, staff studies, information received in confidence, and similar documentary material, when prepared for the purpose of internal communication within the Office or between the Office and other agencies, organizations, or persons, are not available to the public.