If you are withdrawing funds to an address you have not whitelisted in your address book, you will get a warning message.
It is for your own safety to double-check the transaction. You may proceed with the withdrawal if you have entered the right address.
If you regularly withdraw your funds to a specific address, it is advisable that you save them in your address book so that you don’t send funds to the wrong address.
Please refer to “How Do I Whitelist Addresses for Withdrawals?” for more information on how to whitelist an address.