Expert is still quite a mystery to me as well. I'm wondering what it takes to get off of Expert. I am also wondering about the liquidity. Have you tried selling shares on Expert? Maybe it really is better than being Grey. I'm not sure.
Another mystery is why some cuspids get dropped.
If you come across a stock you want to buy online but your broker will not take the ticker, sometimes that can be fixed with a quick phone call.
The trading desk will take a look and determine if the ticker can be added.
I did this recently with MSYN and with VONI.
MYSN is an old ticker that is coming back to life. It's no longer trading unsolicited. That means it's Form 211 has been accepted.