Images cannot be pornographic or show illegal content.
Character images cannot be posted (or linked to) within the text of a story. They can be linked to in author's notes or posted in the Characters section of a story.
Relevant images (character outfits, pictures/illustrations of character homes, maps, etc) cannot be posted (or linked to) within the the text of a story. They can be linked to in the author's notes.
Images that can be used within the actual content of story are limited to page breaks or dividers, or story/chapter banners.