New FT lane-spaces ?s

[Nevadaref]

I am looking for clarification on the new FT lane-space allocation. Previously, a member from either team could occupy any spot along the lane, except for the low block, which was left open by the team entitled to it under the alternation rule.
Has this changed? Basically, if the offensive team decides not to put anyone on the lane, may the defensive players take the middle spots? Could the offensive players move up closer to the free throw shooter if the defense doesn't put anyone there? Also, could the defense put all five players in lane-spaces if the offense leaves one space open or is it a maximum of four along the lane for the defensive team no matter what the offense chooses to do?
The NFHS make it clear or not? Is lining up incorrectly in the upper spaces now a FT violation?
Lastly could someone confirm what the NCAA mens and womens rules on this say. Thanks.