Ahead of Imola, the FIA confirmed that everything it discovered from its forensic checks of the McLaren braking systems was completely above board – meaning it’s back to square one for McLaren’s rivals in trying to figure out just what clever engineering is going on.

It’s since emerged that three separate technical directives were issued to the teams last week, on Monday 12th of May, just a few days before Imola.

TD006A relates to the design of wheel bodywork and tyre treatment, and it’s understood that the correspondence between Red Bull and the FIA regarding its queries about McLaren’s braking system was also shared with all the teams.

Sources have indicated that this TD merely clarified design ideas in the area of tyre treatment, such as those relating to the use of water cooling, would not be allowed – there is no indication that any such systems were in use by any team.

Pre-emptive clarifications and rule changes are nothing new – last year, a mid-season regulation change banned asymmetrical braking systems, with the governing body confirming that there was never any evidence that any team was using such a system.

TD039M pertains to skid block design and is also related to clarifications on how the depth of the plank is measured in scrutineering.

These clarifications pertain to mounting patterns and material usage. Similarly to the wing flexibility tests, these changes are to tighten up the teams’ potential abilities to hit the wear limits of the plank while still passing the minimum thickness checks and, in theory, could have meant some teams needing to raise their cars to not fall foul of the revised checks.

A third technical directive relates to a clarification on how the front floor bodywork flexibility tests are carried out, and is understood to be of particularly minor significance.