While wearing tefillin shel rosh, is one allowed to cover it completely with his talliis?
Answer:
There is no prohibition in having the tefillin covered. However, this is not recommended, for it is best that the tefillin should be seen, as Chazal (Menachos 45b) apply the verse “all the nations of the world shall see that the Name of Hashem is called upon you, and shall fear you” to the tefillin shel rosh. From Orach Chaim 45 (see Eliyah Rabbah) it is clear that the regular way of wearing tefillin shel rosh is for them to be uncovered.
