The citations "indicating the sources in earlier authorities of the decisions in the annotations to the Shulchan Aruch, were not placed by Isserles.
Rabbi Isserles' weaving "his comments into the main text as glosses, indicates, besides upholding the traditional Ashkenazi attitude to a text, that the work itself, meant to serve as a textbook for laymen, had been accepted in Rema's yeshivah at Krakow as a students' reference book.