Thank you for the explanation. Both tickers PBKX and BKX appeared in my MEW but I only received tokens in BKX and PBKX is O. So I'm good, I think except for the temporary confusion 
BKX is the name when token will list on the exchange (ico)
PBKX can change on BKX
What is the difference between PBKX and BKX ticker symbols?
PBKX is the pre-ico token nameBKX is the name when token will list on the exchange (ico)
PBKX can change on BKX