(a) A ruling may be modified or rescinded by:

(1) Publication of the modification or rescission in the Federal Register; or

(2) A rulemaking proceeding in accordance with subpart L of this part.

(b) Unless and until a ruling is modified or rescinded as provided in paragraph (a) of this section, no person shall be subject to the sanctions or penalties stated in subpart P of this part for actions taken in reliance upon the ruling, notwithstanding that the ruling shall thereafter be declared by judicial or other competent authority to be invalid. Upon such declaration, no person shall be entitled to rely upon the ruling.