On complex drawings (with many objects), selecting a discrete group of objects without including every object (in the selected area) can be difficult (for example when an object is hidden by another object). To avoid unintentionally selecting an object, you can `lock' it in position. When an object is `locked', it cannot be selected, deleted, moved, or edited. Objects are locked only when the Edit menu Break Lock Mode option is not selected.
To lock an object:
To unlock an object: