Sort of Punto - and that is the problem. (when you say "in House" I think it was written by NATS for our procedures, with CAA backing of course)
Have a look at the zone map labelled "A N T" (for ALL/NOTHING/TWIN) dividing the LCTR.
That was not published anywhere else - and explains why some pilots sound p***ed off with us sometimes!
On a serious note, I have a PowerPoint presentation that I took to the RAF a few times in the last 2 years. Mike T and I are always happy to come to a unit/organisation/flying school and present it again.