i'don't know if its possible but i configure two type of city protection block with different radius, and that would be very cool if i can assign it for different group whith the permission system:

group 1 : radius 6
group 2 : radius 12
etc...

thanks a lot !

Added 'required-permission' field flag. With this you can make it so the field can only be placed by those with this permission. (i.e. required-permission: preciousstones.vip, would make it so only those with this permission can place the field). If one does not have the permission it will just place an ordinary block without any error messages.