what it will mean is this...
If it's set to a restricted position it will be prevented from opening fully, ie raising the exhaust port top fully. Therefore power output will be reduced, it is there as a restriction because governments have imposed restrictions on what power output learner riders are allowed to have available. If you are a learner rider and find yours is in a restricted position I am not advocating you change it in any way...I am just showing you what can be possible when you pass your test