I may have missed the point, but I think nothing has changed. The charts we use state that departing LHR we are limited to 250 kts until reachimg FL100. Up to now, at the discretipon of the controller, we have been allowed to accelerate beyond that restriction below FL100. From March, they will no longer be able to offer any deviation from the speed constraint. So technically nothing has changed and therefore there is nothing to inform the crews about, although it kwould be nice to know if only so you know not to even ask for high speed.