(a) Generally. No ruling letter will be issued in response to a request for a ruling which fails to comply with the provisions of this part. Moreover, no ruling letter will be issued with regard to transactions or questions which are essentially hypothetical in nature or in any instance in which it appears contrary to the sound administration of the Customs and related laws to do so. No ruling letter will be issued in regard to a completed transaction.

(b) Pending litigation in the United States Court of International Trade. No ruling letter will be issued with respect to any issue which is pending before the United States Court of International Trade, the United States Court of Appeals for the Federal Circuit, or any court of appeal therefrom. Litigation before any other court will not preclude the issuance of a ruling letter, provided neither the Customs Service nor any of its officers or agents is named as a defendant.