Our custom is that none of those called up ascends unless the cantor calls him to ascend, and the cantor only calls someone to ascend whom the gabbai instructs him to, according to the custom of the land. When the gabbai wants someone to ascend, he tells the cantor to call him up, and therefore even the cantor does not ascend without permission. Maharil wrote that regarding the reading of the tochacha (rebuke) in Deuteronomy, which is stated in the singular, there is reason for concern, and therefore the custom is that whoever volunteers reads it. But regarding the tochacha of "If [you walk] in My statutes" (Leviticus), there is no concern, and the custom is also that whoever volunteers reads there. See above, section 135, where I wrote that one need not call the person ascending by name—a mere hint suffices. However, the common custom everywhere is to call "Ya'amod [let stand] so-and-so son of so-and-so."