If you're depositing to Bittrex a memo is required so it knows where to go. If you don't use a memo, you're gonna run into issues and will have a hard time getting your funds back (if you're able to).
You can place a # before the memo on deposit or withdrawal on Bittrex to obfuscate the info, though.
I haven't done a Steem/SBD deposit to Bittrex yet, all my Bittrex Deposits have been incoming BTC to trade for Steem.
Outgoing Steem from Bittrex to my Steem wallet the last time I tried to enter a memo ( last Month ) The transaction failed!
The only way I was able to withdraw Steem from Bittrex was to leave the memo empty.
Do you know if this has changed again???Thanks @matt-a I will put that info in my note book. So much changes so fast and so often with the different exchanges I need to stay on top of this LOL.