Category B: Items with a use may which still may not be moved, according to a Gezeira from the time of Nechemia.

1. M'Yached Lahu Makom (lit. "has a designated place")

An object that has been designated to a specific place, and is not moved during normal use, may not be moved on Shabbat. For example: a piano, a refrigerator, a picture hanging on the wall, a small cabinet, or any other permanent fixture or piece of furniture. If the heavy weight of an object is the sole reason why it is not normally moved, then it may be moved on Shabbat -- e.g. a heavy marble table.

2. Kli Shemelachto l'Issur (lit. "instrument whose primary use is prohibited")

Objects whose main function is for Melacha, but one would be willing to use them for non-Melacha purposes as well, may not be moved on Shabbat. Examples: pen, stapler, hammer, empty pot, phonebook.

It is further prohibited to move such objects in order to safeguard them from being ruined, broken or lost.

The Rabbis, however, permitted moving these objects, if done for one of the following reasons:

a. The object itself is needed for a permissible action (Tzorech Gufo), and no more fitting object is readily available. For example, it is permitted to use a hammer to crack a nut (if one doesn't have a nutcracker).

b. The place (space) that the object occupies is needed (Tzorech Mekomo). For example, moving a pen off the table in order to set the table. It is permitted to choose to use the place where this object is, even if there are other places available. In addition, once the object is in the person's hand, it may be moved to a different location, because once one is allowed to move an object, he may put it wherever he desires.

Items in other Muktzah categories (e.g. Machmat Chisaron Kis, Muktzah Machmat Gufo, etc, or even M'Yached Lahu Makom) may not be moved even for the reasons described above.

3. Kli Shemelachto l'Heter (lit. "instrument whose main use is permitted")

An object whose main use is for non-Melacha purposes may be moved for any reason, but only with conscious intent. Examples: key, storage vessel, garbage can, watch, broom, fan, toy.

Moving such objects without awareness is prohibited, although consciously "playing" with them is permitted.

The following objects may be moved without any restriction whatsoever, since the Gezeira of Nechemia was never placed on them:

a. Torah books

b. Edible food

c. Direct eating utensils -- i.e. silverware, cups, plates, and bowls. (However, some permit the moving of eating utensils only for a purpose.)