Translation:Shulchan Aruch/Orach Chaim/270

1. It is our custom to say the chapter במה מדליקין (from the Mishnah). The Sefaradim say it before Ma'ariv and this is the correct way.

2. There are those who do not say it on Yom Tov that falls on Erev Shabbat and there are those who do not say it on Shabbat of Chanukah. RAMA: We do not act this way during Chanukah. On Shabbat Chol HaMoed we do not say it (customs). And also on Yom Tov that falls on Shabbat we do not say it (Mahari"l, Hilchos Sukkah)