Digging up a pretty old thread here but have a question regarding the dining certificates. Have a couple on the way of varying amounts (have never used them before) and read somewhere that they are essentially like using a travelers check at the restaurant and the restaurant even processes them as such. That being said, if the bill is just slightly under (i.e. $96 bill) can I use a $100 certificate or does it have to be equal to or over the amount of the certificate? Can the certificate be used to cover tax and gratuity as well?