Shortcodes? Displaying description for gallery?

I am losing my mind trying to find a full list of shortcodes for Nextcellent. I can’t figure out how to display a gallery’s description under a grid of pictures. (In this case, the description contains credit for the person who took the photos, so it has to be displayed).

Any help is appreciated.

http://ww.wp.xz.cn/plugins/nextcellent-gallery-nextgen-legacy/