"We Don't Talk About Haman..."

Comment of Rabbi Moses Isserles:

Some [Rabbinic authorities] have written that there is a custom [when reading the Megillah] to say four verses of redemption in a loud voice: [These are] "A Jewish man..." (2:5); "And Mordechai went out..." (8:15); "The Jews had light..." (8:16); "For Mordechai the Jew..." (10:3), and such is the custom in our countries [sources: Hagahot Maimoni; Kol Bo; Avudraham]. And then the reader goes back and recites those verses again [for the congregation].

They also wrote that children have the custom to draw pictures of Haman on trees and stones, or to write the name of Haman on themselves, and to rub one [picture or name] against the other in order to destroy his name, as the verse states, "You shall completely destroy the mention of Amalek" (Deut 25:19); and "The name of the wicked shall rot" (Proverbs 10:7). From this the custom also spread that we make noise at the name "Haman" when we read the Megillah in synagogue [Avudraham]. And we must not neglect any custom or ridicule it because it was not established without a good purpose [Beit Yosef].