We had a piece of ESM kit in the old R30 (Temporary Ops Room) at Neatishead, I think it was supposed to be from a Vulcan.
If memory serves, it was referred to as DIALECT ... I never heard it called by a Rainbow Code, but as an FC who had passed the controller training, I was never invited to use it, Does anyone remeber what it was? ORAC?:
Probably still here:
Which is well worth a visit if you're in the area.
Friedlander