The diary card is a paper that one fills out in DBT. The top section has to do typically with troublesome feelings, urges, and behaviors, as well as medication taken. The bottom half has to do with recording the DBT skills used. The most current one from the second edition(of official books by Marsha Linehan(creator of DBT)) is in this link:
http://acumencs.com/wp-content/uploa...Diary-Card.pdf

Hope this helps, though not sure it'll be very helpful if you have done or aren't doing DBT.