Mat Coch writes:

The FIA introduced a late change to the regulations today, just minutes before the second practice session for this weekend's Australian Grand Prix got under way.

After the first practice session it became clear that teams and drivers were operating the moveable rear wing (DRS) at every opportunity.

Regulations initially allowed teams to use the device at any time during practice and qualifying, while its use during the race is restricted to the front straight, if the driver is trailing the car ahead by less than a second at the penultimate corner.

The complexity and inconsistency of the regulations have confused many, drivers, teams, media and fans alike, and have come under fire during the weekend as a result.

A note to the teams was released at 16:21, just nine minutes before the start of the second free practice session, stating that use of the DRS would be restricted during the final thirty minutes.

Furthermore in the final five minutes the FIA tried both 'DRS Disable' and 'DRS Enable' functions, essentially switching the system on and off centrally.

The change was made to give the FIA an opportunity to test the system in race trim ahead of the Grand Prix on Sunday. For the watching masses the late change caused a great deal of confusion, with several teams trying to explain the situation to fans via their Twitter feeds.

For the moment we understand the final practice session and qualifying tomorrow will adhere to the standard regulations, and drivers will be able to freely operate the device.

That said, one gets the impression that they're making some of this up as they go along.