How to Automatically Delete Unused Reference Headers
Unused reference lists will remain if you have deleted components but have not deleted their reference list headers. You can choose whether or not unused cross reference headers will be deleted automatically when the cross references are updated for the project.
Go to the Options tab page.
Tick Delete Unused Headers if you want unused cross reference headers to be deleted automatically.
Untick this option if you want to manually delete cross reference headers.
If you are updating the cross references on a single sheet from inside Elecdes (Cross-reference this sheet), then unused headers will only be erased if they are selected during that procedure as part of the set of blocks and symbols to have their cross reference information updated.