The law in relation to cause of action estoppel as developed in patents and registered designs cases applied to trade mark cases, so that (i) a person who attacked the validity of a trade mark was under a duty to put his full case in support of that attack at trial; and (ii) if he were unsuccessful, he would be barred by cause of action estoppel from attacking the validity of that trade mark in subsequent proceedings whether or not on the same or different grounds. Such an estoppel did not however extend to bar a claim for revocation of that...