Pink current tickers got suspended by SEC too. $COUV & $RBII were Pink current when they got suspended. I think the SEC suspend the tickers whose managements released news that are not true, claimed what they weren't.
Tickers that are involving in Court related (bankruptcy, custodianship,...) are usually not get suspended, imo. I think Custodianship & RM plays are pretty safe from suspension, jmho.
tk