1. The Mishnah discusses locations where an Eruv Chatzeros may not be placed.
2. The Mishnah discusses locations where an Eruv Chatzeros may be placed other than in a typical house in the Chatzer.
3. The Tana Kama and Rebbi Yehudah disagree about the status of a person who lives in a storehouse.
4. Rav Yehudah: In the places where an Eruv may not be placed, a Shituf may be placed.
5. If all of the residents of the Chatzer eat together when Shabbos enters, the bread on the table may be considered an Eruv.
A BIT MORE
1. These include a guard's hut at the entrance to the Chatzer, and various types of porches. Even if one lives in such a place, his presence has no effect on the status of the Eruv.
2. These include places where people store animals, straw, and wood.
3. Tana Kama: If a person is granted permission to live there by the owner of the storehouse, he must be included in the Eruv just like every other resident of the Chatzer. Rebbi Yehudah: If the owner stores Muktzah items in the storehouse, the owner's participation in the Eruv is not cancelled by the dweller's lack of participation in the Eruv.
4. The only exception is that a Shituf may not be placed in the airspace of the alleyway (since it is not a protected area).
5. Since they all partake from this bread, it may be considered their Eruv even if it is technically owned by only one person.