→Which Is the Right Side?
* The Chelkat Yakov explains the Mordechai to mean to add that even though when the vestibule is open to a courtyard and the main room to the public people will use the vestibule more often as an exit than an entrance, nonetheless, since the main room is used more than the vestibule, we view the entrance between the vestibule and the main room as an entrance and not an exit. In this he is proving that the rule of majority of walking is trumped by majority of usage.
* Igrot Moshe 4:43:4 writes that rule of majority of walking trumps the rule of usage and also the rule of doorway. His logic is that the room that is used more is only an indication of which way people walk a majority of the time but the main factor is the way people walk. He holds that the way people enter a majority of the time is an application of the deoritta halacha to put a mezuzah on the right as a person enters. </ref>
## '''Majority of Walking''': If the position isn't determined by entry or by which is used more frequently it can be determined by which room people walk from one room to another; if majority of the times people enter in one direction the mezuzah is placed on the right of that direction.<ref>[http://www.yutorah.org/sidebar/lecture.cfm/788640/rabbi-hershel-schachter/the-laws-of-mezuzah/ Rav Hershel Schachter in “The Laws of Mezuzah” (min 34-42)] holds that the factor of looking at the majority of the way people walk one room to another trumps the rule of the way the door is placed. Aruch Hashulchan 289:8 and Igrot Moshe YD 1:176 agree
. However, Igrot Moshe 4:43:1 further. Hamezuzah Vehilchoteha 11:12 holds that this factor is to be used after the door rule. Chelkat Yakov YD 161 agrees.</ref>
## '''Doorway''': If the position of the mezuzah cannot be determined based on which direction is used for entry or which room is used more frequently it can be determined by the door. Since the door generally swings into the room (besides the outermost door of the house) the way the door swings can be considered the way one enters the room and the mezuzah is placed on the right side entering the room.<ref>Menachot 33a, Shulchan Aruch YD 289:3, Aruch Hashulchan 289:6</ref> However, if the mezuzah is determined based on the previous factors it doesn't matter which way the door swings.<ref>Mordechai cited by Bet Yosef YD 289, Shach 289:6, Aruch Hashulchan 289:7, Igrot Moshe YD 4:43:3, Hamezuzah Vehilchoteha 11:11</ref>
## '''Doors to the Outside''': Any door that goes from a place that is exempt from mezuzah to a place that is obligated in mezuzah should have the mezuzah on the right side entering into the place that is obligated in mezuzah. The mezuzah on the front door or back door of a house is always placed on the right side going into the house since the house is obligated in mezuzah and the street isn’t. A walk-in closet which is less than 4x4 amot the mezuzah is put on the right side going from the closet into the room since the closet isn’t obligated.<ref>[http://www.yutorah.org/sidebar/lecture.cfm/788640/rabbi-hershel-schachter/the-laws-of-mezuzah/ Rav Hershel Schachter in “The Laws of Mezuzah” (min 34-42)] explained that this is the first factor by which a person determines on which side of the door the mezuzah is placed.</ref>