The Board hereby determines that the following authorizations are not licenses “with reference to an activity of a continuing nature” within the meaning of 5 U.S.C. 558(c):

(a) Authorizations granted for a specified period of 180 days or less; and

(b) Authorizations, other than those granted under section 401 of the Act, that by their terms are subject to termination at an uncertain date upon the happening of an event, including fulfillment of a condition subsequent or occurrence of a contingency.