I know how to create an extension that adds custom link types, but is there a way to get rid of the link types that come with RTC?

I would like to make it so that a user could not create a link of type Related.

Also is there a way to change the display name of the links that come with RTC?

I already tried adding a custom link that has the same id as one of the links that comes with RTC, and it did not work.