I had an interesting one yesterday.
Cleared to descend FL90, direct to waypoint x, information is 'Yankee' QNH992mb.
I guess MATS would advise against clearing descent to a FL and then mentioning the QNH in the same transmission. I think it was in response to my call stating that we had information X-Ray. The QNH had changed from 991mb and the controller wanted to advise us of the change. I must admit I almost felt I detected a hint of 'I shouldn't have added that on' just as the controller said 'Information is Yankee, QNH....992mb'! I made a point of emphasising my cleared FL and the fact that I had copied the QNH as 992. Probably non standard in the way I did it!!!
PP