hey there... yup I have

Q. Is my significant other allowed to work?
A. Yes, provided the union is official (marriage, civil partnership), and regardless of nationality.

but it's on a forum... where can I find this information on an official channel as immigration? I have been looking everywhere and I can find documentation on how to apply for ther registered partnership, but not that this partnership will grant a visa. If I look at the family reunion visa option it only mentions the word spouse.
That's why I am puzzled...
So, if he comes here and we do a registered partnership, then what?

Thanks again for any feedback... just very frustrated...