[lzzjp]

I found this link with a very detailed explanation about "rights of entry to and stay in the UK under the Immigration Rules for non-European spouses/ civil partners/unmarried partners, of those settled in the UK."

I am sure you might clarify some questions here:

Marriage and partnerships: UK Rules

 

[Joppa]

Yes, but you get the same information on UKBA site, and it's official.