Using the Lock Luminaire command prevents any modifications to the selected luminaire(s) until they are unlocked. Luminaires may be locked or unlocked one at a time, by drawing a "window" around a group, or all at the same time.
Locking
Single: To lock one luminaire, from the Modify menu select Luminaire - Lock - Single, or in the Luminaire Toolkit click on the Lock button. 
With the pick box attached to your cursor, click on the luminaire that you wish to lock. You can continue to select additional luminaires if desired. The Command Line (lower-left corner of screen) shows the number of luminaires selected. When finished selecting, right click to complete the command, or press the Esc key to cancel the action.
Window: From the Modify menu, select Luminaire - Lock - Window, or in the Luminaire Toolkit click the little down-arrow next to the Lock button and select Window. with your cursor, click two points defining a rectangle ("window") encompassing the luminaires that you wish to lock. After the second point is clicked, the Command Line shows the number of luminaires selected. Right click to complete the command, or press the Esc key to cancel the action. Note: Any selected luminaires that are already locked will remain locked.
All: From the Modify menu, select Luminaire - Lock - All, or in the Luminaire Toolkit click the little down-arrow next to the Lock button and select All. The Command Line shows the number of luminaires selected. Right click to complete the command, or press the Esc key to cancel the action. Note: Any selected luminaires that are already locked will remain locked.
Unlocking
Single: To lock one luminaire, from the Modify menu select Luminaire - Unlock - Single, or in the Luminaire Toolkit click on the Unlock button. 
With the pick box attached to your cursor, click on the luminaire that you wish to unlock. You can continue to select additional luminaires if desired. The Command Line (lower-left corner of screen) shows the number of luminaires selected. When finished selecting, right click to complete the command, or press the Esc key to cancel the action.
Window: From the Modify menu, select Luminaire - Unlock - Window, or in the Luminaire Toolkit click the little down-arrow next to the Unlock button and select Window. with your cursor, click two points defining a rectangle ("window") encompassing the luminaires that you wish to unlock. After the second point is clicked, the Command Line shows the number of luminaires selected. Right click to complete the command, or press the Esc key to cancel the action. Note: Any selected luminaires that are already unlocked will remain unlocked.
All:From the Modify menu, select Luminaire - Unlock - All, or in the Luminaire Toolkit click the little down-arrow next to the Unlock button and select All. The Command Line shows the number of luminaires selected. Right click to complete the command, or press the Esc key to cancel the action. Note: Any selected luminaires that are already unlocked will remain unlocked.
Note: Luminaires that are in a locked Project may not be unlocked using these commands. The Project itself must first be unlocked in Project Manager.