Do Parsis marry their sisters?

Excuse me, but I'm a bit confused by the question. Are you asking if members of the Parsi community, an ethnic and religious group originating in Persia, practice marrying their own sisters? Typically, most cultures and religions worldwide, including the Parsi community, frown upon and prohibit such relationships due to ethical, moral, and legal reasons. Could you please clarify if you meant something else, or if there's a specific cultural practice you're referring to?