Arbortext IsoDraw > User's Reference > Menus > Element Menu > Lock
  
Lock
You can use this menu command to lock individual objects on a layer. The locked objects remain visible on the screen but can no longer be activated or edited.
Where drawings are complex and involve numerous individual elements, it can be extremely useful if some of the elements are made inaccessible to the arrow cursor, thereby preventing them from being moved inadvertently, for example.
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If you have organized your drawing into layers, you can easily lock all the elements on a given layer in a single operation by using the setting options offered by the layer window (see Show Layer Window).