Don't know if this has been added to the new version yet but it is missing in 4.0.2 - custom headers
When individuals are merged, the individually ID that no longer exists should be given a 301 redirect to the other
When a person has been deleted, a 404 should be given or if ID's are reused, a 302 redirect to the welcome page until that ID is used again.
The above will not only benefit the viewer, it will also help search engines update their index.
If a person calls an individual page where the ID does not exist, a 404 should be returned.
When I uploaded my gedcom, I had it use the existing RIN's. For some reason, I am having many people try and call pages for people that do not exist. What they get is a page with all data marked private. I suspect they think they can guess the ID. What they should get is a page that returns a 404 header and text that explains there is no Ixxxxx in the database.
