(a) This part governs HUD's issuance of guidance documents.

(b) HUD and the Administrator of OIRA may jointly determine that a guidance document is exempt from some or all of the requirements of this part for exigency, safety, health, or other compelling cause.

(c) This part is not applicable to any guidance document that is authorized by law or contemplated by or incorporated into a contract, including:

(1) Handbooks and mortgagee letters issued by the Federal Housing Administration; and

(2) All Participant Memoranda and Multiclass Participant Memoranda issued by the Government National Mortgage Association.