Hi Mark
Tris is correct in what he says, however one must consider the interpretation and application of the rules.
My opinion for what it's worth...!
I believe there is an assumption in the rules, aimed at pilots who may want to fly ad hoc wherever they please, that precludes permission.
Let me try to clarify my assumption:-
If you wanted to film in an open area some footage of your grown up Son or Daughter playing with their children, having obtained your Son/Daughters consent, will you be falling foul of the rules if you take off within 30 meters, I think not...
because you would be deemed to have those people under your direct control.
As seen here from the Rules......
(4) Paragraphs (2)(d) and (3) do not apply to the person in charge of the small unmanned surveillance aircraft or a person under the control of the person in charge of the aircraft.
I believe that the same can be said of buildings etc provided that you have obtained the appropriate permission.
Flight over crowds etc is I believe different, because you cannot be deemed to have obtained individual permission.
However a flight over a group of your friends who agree to the overflight, is again in my opinion acceptable.
I have been involved with the UK Health & Safety Executive over a number of years, (not with regard to UAV's), and have seen common sense prevail in many contested interpretations of the "Rules", generally the application of this section of the CAA Rules, is intended to ensure that individuals do not infringe a third party's right to privacy, or inadvertently put them or their property in jeopardy.
I think its down to common sense, if you fly responsibly and with the relevant permissions, then I don't believe you will be challenged.
Good luck with the wedding...
Waylander