The index of this item in its parent container (if any).

The unique identifier for this location marker. Note that it may happen that content gets duplicated, e.g. from source to target in a paragraph unit, and that location markers in that case also get duplicated. Therefore, it is not possible to guarantee that location marker ids are unique throughout the document, but at least, in such cases, the two locations should be closely related.

When this item is inside a markup data container, this property provides access to the parent container.

Convenient accessor to the source or target paragraph container that the item appears in.

The Unique ID associated with an object may be used by implementations during operations such as segmentation