There's no clearly defined line. This is by intent. The idea is to send a message - you can be a bit risque, but don't cause us problems or we'll suddenly decid

There's no clearly defined line. This is by intent. The idea is to send a message - you can be a bit risque, but don't cause us problems or we'll suddenly decide whatever your percentage is is too much. So many rules, especially in compliance, are like this. They all boil down to "we'll look the other way for minor violations but as soon as you piss us off, you have our full attention and not in a good way". Keeps everyone on their toes and is probably better than trying to define some kind of exact threshold (which everyone would then brazenly ride exactly on the edge of). Note I'm not agreeing with it in the slightest.