Rule 5.4. Recognition to address the House
When any member wishes to speak in debate, he shall press his "floor" or "question" button to register his desire. The presiding officer shall recognize those members whose names are registered in this manner. If a main motion and a debatable subsidiary motion are before the House, the presiding officer may differentiate between those members wishing to debate each motion.
Mason's Manual: Sec. 91
HR 3, 1973; HR 4, 1st Ex. Sess., 1988.