Q. When learning about tznious and their halachos sometimes I come across the category Das Yehudis.
Can you kindly explain if this is derrobonim, doreisa? What is its status and how can I understand what it is. How should we view Das Yehudis in regards to tznious halachos.
Thank you
Ps, Can you kindly explain what the difference is between Das Moshe and Dad Yehudis.

A. Daas Moshe basically refers to all mitzvos ordained by the Torah, in practice it is used in reference to Biblical issues involved in establishing marriage or causing divorce. (Kesuvos 72a, Rashi and Meiri ibid.).
Rashbo (Tesh. 5: 246) asserts that when the word “Veyisroel” is added to “Kedas Moshe,” as when used under the chupa, it includes also Rabbinical mitzvos.
Daas Yehudis, reflects Rabbinical mitzvos usually involved in women’s tznius and modesty issues. These are based also on customs and practices that women accepted for generations, and sets them apart from other nations. (Rambam H. Ishus 24: 12, Shulchan Aruch E.H. 115: 4, Rahi and Meiri Kesuvos 72a).
Mishna (Kesuvos ibid.) quotes some cases of daas yehudis, such as in some instances going out with hair improperly covered, spinning thread in public when it causes body exposure, or engaging in conversation with all men etc.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a