I have what may sound like a stupid question but will ask all the same, otherwise it will keep floating in my head.
When a lead restriction prohibits the player from leading a particular suit the restriction continues to apply as long as the player retains the lead.
But when the restriction requires the player to lead a particular suit there is no mention in the laws that the restriction continues to apply as long as the player retains the lead.
Why ? I haven't been able to figure out the answer.