In a rapidly changing series of events (so much so that this will probably be out of date by the time you read it), the exhaust blown diffusers - used by most teams - have been banned, allowed, and now the position appears undecided.
The whole debacle has annoyed many associated with the sport, and the disagreement reached a very public boiling point during the press conference on Friday afternoon where a very heated debate took place between Red Bull's Christian Horner, and McLaren's Martin Whitmarsh.
However, things seemed calmer by the evening, as the FIA announced they had agreed more lenient terms with the two main protagonists, Renault (Red Bull) and Mercedes (McLaren).
Saturday morning, things had changed again. The FIA decided that they would not be able to be as lenient with the Really powered cars as they had hoped on Friday.
This clearly angered Horner and chief Red Bull designer Adrian Newey, yet their two cars managed to acheive 1-2 in qualifying.
After qualifying, the FIA performed a further U-turn, confirming that if all teams are in agreement, they rules can revert back to how thet were pre-Silverstone.
It's a rather complicated issue even for the teams and drivers tofor anyone to understand, let alone fans - something which Mark Webber referred to in the post qualifying press conference.
The best person to explain it in detail is everyone's favourite technical guru, Scarbs. Visit scarbsf1.wordpress.com for more!