Frame object: True if the specified frame is locked. The frame anchor indicates where the frame will appear in Normal view. You cannot reposition a locked frame anchor. Read/write Boolean.
Shape or ShapeRange object: True if the specified Shape or ShapeRange object's anchor is locked to the anchoring range. When a shape has a locked anchor, you cannot move the shape's anchor by dragging it (the anchor doesn't move as the shape is moved). Read/write Boolean.
Remarks
A Shape objects is anchored to a range of text, but you can position it anywhere on the page. The shape is anchored to the beginning of the first paragraph that contains the anchoring range. A shape will always remain on the same page as its anchor.