Reply To: Can a “Kosher” Restaurant Advertise it also is “Halal”

Milhouse, the Rosh says that that stopped with Abaye and Rava. Even more so today when rabbanim have access to more sefarim. According to your opinion, a Chassid cannot rely on Rav Moshe’s pesakim and a Litvak cannot rely on Rav Wosner. A Yekke cannot rely on either. The Briskers are certainly wrong for relying on the Rambam fr learning.BTW, FYI many Sephardim learn in Ashkenazi yeshivot and vice versa.