A no-oral-modification clause does not prevent parties from orally varying a contract, and a party exercising a show cause power who has closed its mind to any cause that might be shown acts in breach of an implied obligation of good faith.
The full text is available to signed-in members, including the 24 later cases that cite this judgment.
3 of the 24 citing cases carry a classified treatment. How each court treated it is available to signed-in members.