This document discusses different types of captions used to complement images. It defines a caption as a short piece of writing that provides context for a picture. The document then outlines guidelines for writing captions and describes several common types: identification bars name who is in an image; cutlines name who and what they are doing; summaries provide who, what, when, where, and why; expanded captions add how and quotes; and group identification captions name everyone in a group image. Examples are provided for each type.