Thanks hihover, your reference to LASORS A7 does seem to answer, in part at least, the query I had.
It does not mention specific classes of airspace only controlled airspace.
You could argue that all the classes of airspace are controlled but with different restrictions so if you are IMC in class G airspace thereby requiring to comply with IFR you are outside the privileges of the agreement.
It would appear to be next to useless as a rating in the UK on UK registered aircraft or am I missing something.
It also mentions no instruction and no hire & reward which again renders it next to useless.