Ripple addresses are composed of a string of 34 characters.
With Ripple, a Tag is required to associate your transaction with your account. On Bitfinex, a tag is provided for each of your wallet deposit addresses.
If you are depositing XRP, you can find the Ripple address and tag on your Ripple deposit page.
If you are withdrawing XRP to a merchant or another exchange where all XRP funds deposit to the same address, you must copy the tag they provide you, and paste it into the Recipient Tag field on the Bitfinex Ripple withdrawal page.