The paper studies the spelling of -ás/-és forms of set phrases with a verbal head. This is made necessary by the fact that a long list of exceptions appended to the article no. 126 of the Rules of Hungarian Orthography makes the validity of that paragraph doubtful. Furthermore, prior to the empirical investigation, it was also debatable whether those exceptions are in fact forms that occur frequently in everyday spelling practice or whether they just get inherited down the tradition of spelling codification from rulebook to rulebook, from dictionary to dictionary. The study reported here gives unambiguous answers to the above dilemmas. Since in some cases the derivatives of traditionally spelt phrasemes occurred either infrequently or practically not at all in the corpora we have investigated, and the contexts also exhibit a number of irregular properties, the author thinks that a rethinking of the article no.126 is by all means justified.