SYD-MEL sectors sold within Australia are sold as J class only - but you get to sit in the First Class section!
BA yes does code-share certain sectors within AUstralia but one can only book them in conjunction with an international BA flight arriving into Australia. You cannot book them specifically on a BA flight number in the hopes of gaining extra EC points.
[This message has been edited by Guy Betsy (edited 06-06-2001).]