1. It is forbidden to erect a tent on Shabbos and Yom Tov even if it is a temporary one. However this refers to the cover, but the partitions are permitted. A partition is forbidden only when it is erected to permit a Sukkah or to permit carrying. RAMA: A partition erected for privacy is permitted (Tur), therefore it is permitted to hang a curtain in a doorway even though it is 1) permanent (Beis Yosef), 2) and a Paroches in front of an Aron Hakodesh, provided that one does not form a cover a tefach wide (Beis Yosef; Kol Bo). It is likewise permitted to erect a partition against the sun or cold, or in front of candles so as to prevent the wind from extinguishing them (Mordechai). It is 3) forbidden though to erect a partition before a candle in order to have a relationship, or before holy books in order to have a (2) relationship or to defecate, unless it was expanded a tefach before Shabbos, for then it is permitted to add to it on Shabbos. (Mordechai)
2. Beams of wood stretching from one side of a boat to the other, if they are a tefach wide, or even if their width is less than a tefach but they are placed within three tefachim of each other, it is classified as a tent and is permitted to be covered with tarpaulins on Shabbos because it is a temporary addition. For this reason it is permitted to add the remainder of a covers onto a cover that is already a tefach open. The tefach they were referring to is besides the spool.
3. When setting up a bed, it is forbidden to place the legs first and then place the boards above them, rather one must first hold the boards in the air and place the legs beneath them. However, this applies to legs which comprise of boards similar to the walls of a box, but the legs of our beds and regular table legs may be placed in any manner seen fit.
4. A bed interlaced with ropes, if there is a gap of three tefachim between each rope it is forbidden to spread a sheet over it because one is making a tent, and likewise it is forbidden to remove the bottom sheet because it is dismantling a tent. If there was a pillow or a cover or a garment spread a tefach wide before Shabbos it is permissible to continue and cover the entire bed.
5. A chair comprised of different sections and in order to sit on it one opens the chair, which in turn unfolds its leather, and when its use is terminated it is closed and its leather folds, is permissible to open initially.
6. When arranging barrels on top of each other in such a way that one is above two, one should hold the top one in the air and place the bottom ones below. However one should not place the bottom barrels first and then place the top one above them.
7. One is permitted to place a book on one side and a book on another side and a book on top of them. RAMA: because the space is not needed. (Tur; R"an)
8. Any tent which is slanted so that it is not a tefach wide at its top, nor a tefach wide within three tefachim to its top is a makeshift tent, and one who erects it on Shabbos is patur (exempt).
9. A strainer positioned in order to strain dregs whose mouth is stretched in all directions is considered tent-making, and is therefore forbidden to set up.
10. A folded cloth which has strings attached before Shabbos may be spread out and dismantled, and the same applies to a screen.
11. A Choson (wedding) canopy which is not a tefach wide at its top, nor a tefach wide within three tefachim to its top may be erected and dismantled, because it is preset to do so, provided that it does not drape down a tefach below the bed.
12. When hanging up a curtain and the like, care must be taken that the curtain does not form a tent at that time. Therefore, two people are required to hang up a big curtain; one person is forbidden. Even ten people may not erect a canopy with a roof because it is impossible to prevent the canopy from rising a bit off the floor and creating a makeshift tent.
13. A barrel must not be completely covered with a cloth because of Ohel, rather a small area must be left uncovered. This only applies if there is a space of a tefach (between the cover and the contents), but if there is not a space of a tefach it is permitted, because an Ohel is not formed.