The credit/debit card 'add the tip' may result in the actual amount that the servers get is reduced by the credit/debit card 'fee' that the establishment pays to the card company/bank.
I found that out by talking to a few servers. One place I frequent takes 7% of the 'tip' for "handling". So, as I am very satisfied with the service at this place, I leave the tip in cash!
Yes, there are some places that have what mbhydro listed above, and others that have a blank line to insert the $$ amount of your choice.
Dining out is becoming really tough with the restrictions here, as winter is here, and indoor is limited to 25% occupancy. NYC just closed down all indoor dining!! (Bummer)
