And thus the cosmic cycle continues...
CM is correct. Any class of airspace can theoretically be the subject of a designation under 99A. It's about mandatory blabbing in the designated area, not about the class of the airspace in that area. It's been used many times because, as we know, more blabbing equals more safety. However, come the year 2003 99A will be repealed.
And another 'blast from the past' was GF's epiphany about class F.
It astounds me that there's anyone left who doesn't realise that airspace arrangements and procedures in Australia are determined by the JMSUAYGA Procedure.