Dead CLZ Link Question

I’m doing a little Spring cleaning of my CLZ Collector movie entries, and one of those cleaning task’s is the updating the external links for my movies. In doing so I often find these CLZ Core for Movies links. They appear to point to a useless dead CLZ webpage.

What are they for. Do I need to keep these? Is it ok to delete them?

Additionally is there anyway to modify or add to the list of links that automatically add external links when updating an existing or adding a new movie?

That Core site does not exist anymore. It is safe to remove those links.