H_KARLUK, on Dec 18 2008, 03:27 PM, said:
The EBU L&E committee do not like the word "ban", they just fail to allow/permit.
In TRS was only briefly allowed under the previous arrangements for licencing systems and conventions, that was replaced by levels 1/2/3/4/5 over a decade ago. TRS only had an experimental licence - allowed in national events of 32 board matches or longer.
The relevant year books of the L&E committee show:
EBU Licenced System: June 1987
TRS - Experimental Licence application pending
EBU Licensed Systems: September 1988
TRS - Licence lapsed
As I remember, a successor to TRS was the DAW pass. The main difference was that the "responses" to the medium opening pass in TRS were artificial negatives 1C/1D and natural GF positives, in DAW I think there was one artificial GF positive.
DAW had an experimental licence after TRS. Under the new scheme, experimental licence were replaced by level 5, which was expressed in terms of other EBU and EBL permitted systems/conventions.
Robin