Leaving a Yad inside a Sefer Torah

Hi,

One may not leave the Yad (pointer) inside the Torah between aliyot (readings) to mark the correct spot, since nothing may be left atop a Torah scroll. The sole exception is that we leave a cover atop a Torah scroll in between aliyot, but this is for the sake of the honor of the Torah.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 1:37)

Have a great day,
Mordechai