Only on his tallit.
From http://www.haretzion.org/faculty/ramim:
Rav Doniel Schreiber [YHE ’86] has been a Ram at Yeshivat Har Etzion since 1994, and he is the founding Dean of the Yeshivat Har Etzion Center for Torah Leadership. He has Semicha from the Rabbi Isaac Elchanan Theological Seminary and an MA in Medieval Jewish History from the Bernard Revel Graduate School. Rabbi Schreiber also lectures regularly in halacha in the community of Alon Shevut, and has been delivering a weekly evening halacha shiur to men and women in Jerusalem since 1997, first at Kehillat Moriah until 2003, and then at the Hildesheimer Shul until the present. He is the author of an Internet shiur entitled “The Laws of Shabbat” for the Israel Koschitzky Virtual Beit Midrash, has published articles in various books and Torah journals, and has served as scholar-in-residence in various communities in Israel, the United States, and South Africa. His shiurim emphasize reaching a clear halachic conclusion while showcasing the dynamic and conceptual system of halacha as it emerges from the gemara, rishonim, and poskim. Rabbi Schreiber and his wife, together with their eight children, live in Alon Shevut.
