We had a lot of InterTrac links enabled on fedorahosted.org. In order to migrate to pagure, they should be supported and converted by pagure-importer.
Not sure if we need InterPagure links as well or just want to convert to 'plain' links, nevertheless I filed a feature request against Pagure.
The list of InterTrac links on fedorahosted.org can be found at https://pagure.io/fedora-infrastructure/issue/3098 (also, that ticket does not look like it was converted properly)