Martin (and others),
As others have already said, URI body rules use a list of valid TLDs to help with recognising URIs embedded in body text and this list is currently hardcoded into SA.
Thank you for the explanation and the rule. I've put it in place and it appears to work fine with my first set of tests.
which I've tested fairly carefully. All the subrules except __MG_TLD1 work exactly as I wanted them to. I can live with __MG_TLD1 not working until either a current SA maintenance version is released with an extended list of hardcoded TLDs or a version using a configurable list appears.
I suspect they'll allow a configurable list of TLDs going forward. Best, Jesse Stroik