Block

Toggles an existing block between on and off. (A block may not be toggled in the 3D View, the concept of Block definition in this view differs from other views. See Blocks)

The Block tool displayed above is used select whether you want an existing block to be on or off by clicking it with the accept mouse button.

When the Block tool is on, then certain processes will only be carried out on data which is selected by the particular block definition. For further information about defining and using blocks, refer to the Block command.