Use locking to prevent the properties of a point group or point list from being modified in a drawing.
Point Groups
A locked point group cannot have its properties changed. It cannot be updated (if it is out-of-date), deleted, or overwritten.
A locked point group has 
next to it in the Prospector tree and the point group list view. The icon is displayed only if the Toolspace tree drawing state icons are displayed.
Locking a point group does not lock the points in the point list. You can lock points individually in the Prospector list view, or you can lock all the points in the point group list at the same time using a single command.
Point Lists
A locked point cannot have its properties changed in the drawing. A locked point has 
next to it in point lists such as the Prospector tab Points list view. The icon is displayed only if the Toolspace tree drawing state icons are displayed.
Use a single command to lock or unlock all the points in a point group’s point list.