Or you could have the {caption} (or any other variable, such as {client}) display as one of the contact sheet labels. Go to Preferences -> Contact Sheet and look at the "Labels" section. Also note that when you click Set Info Text, it will change the Info text that appears in the Preview Window to what you just used. So, I use multiple Info Text Snapshots so I can change among different sets of Variables I might be interested in seeing either in the hover or in Preview. See the Attachment for examples.