CAP168 Licensing of Aerodromes
Thanks! - that sounds like exactly the sort of answer I was hoping for.
(Plus, I suppose, any comment on whether it was safe to assume that a club's insurance covered landing on unlicensed runways unless otherwise stated, or whether it was prudent to assume that a club's insurance didn't cover landing on unlicensed runways unless otherwise stated. For a specific example, of course, I'd ask.)