Yes. While deposits taken should not be "banked" as revenue until they are redeemed against a service or product purchase, Slick will help you balance your cash flows by showing a "Deposits" line in your cash up screen, which will display the sum total of all deposits taken in that time period, minus any deposits refunded. Click here for more information on refunding deposits.
Please note that the Deposits line in cash up is not added to your Total Takings (as it is not yet considered as revenue). It is there to help with balancing your books at the end of the day, week or month.
Please also note that deposits taken will not show up in your revenue reports until they are redeemed at checkout. You can see a list of credit on account by client name in Menu > Settings > Outstanding Deposits.