But we should also take into account those users which are not ‘most’ end users, for example delivery drivers which might request those permits. For them it is important to distinguish between ‘I might get a permit’ or ‘it’s not possible to get a permit for this’ - exactly the question of Anthony.
TBH, I do think that the tagging scheme is insufficient for the current use and should be reconsidered. Alternatively, a motor_vehicle=no´, motor_vehicle:concational = yes @ ( some specific conditons)` might be appropriate here