T'hilas Hashem, the standard sidur (prayer book) of the Lubavitch chasidim, includes, passim, rulings of their first rabbi ("the Rav"), copied from his own sidur. The rules printed before halel ...
Lubavitch prayer books include the words אָב הָרַחֲמִים where other prayer books have אַב הָרַחֲמִים (specifically, in the amida of musaf and mincha of Shabas Shuva, and in a prayer said after ...
Why do Chabad siddurim always print Veshameru before the Shabbat Ma'ariv Amida, even while also noting that the Chabad custom is not to say it? Are there any groups that use the Chabad Nusach Ari ...