Label key
The Label key can be used to label almost all elements.
Pressing Label followed by an executor, preset, group or a lot of other objects, will open the Enter Name for... window. Here you can type a new name for the object.
You can label multiple things at the same time. And if you end the name with a space and a number, then the objects will be enumerated.
E.g. you want to label fixtures 1 to 10. The first should be "Dimmer 1" and the last one should be "Dimmer 10".
Label Fixture 1 Thru 1 0 Please now type in Dimmer 1 in the Enter Name for... window. That's it.
Advanced Functionality
If you press and hold the 
key and then press the Label key. then you get the Assign command.
This can be used as a shortcut in different functions. For example when assigning fade times, other functions to executor keys or when patching fixtures. Read about it by following the link above or below.
Related links