In a method of working a recessed portion 2 in a headrest stay 32 which is provided in the stay portion 32 of the headrest stay 3 formed of a pipe, a recess 2\u2032 is preformed by pressing against the stay portion 32 an outer peripheral portion 4a of a first punch roller 4 for preforming having a rounded portion 47 on the outer peripheral portion 4a in a side view. The improved methodology involves varying the temperature of the feed to the heavies removal column between start-up and normal operation. The designation of the identifier may automatically designate a subject identifier as a message text sequencer based upon user predetermined attributes.