CoPress

Has anyone seen a plugin that allows you to add hidden editorial comments to a story? For example, you could use it to add a suggested headline to a story, a comment that more info will be added later, or a verification of name and phone number for letters to the editor. It would have to be something akin to a PHP comment that won't display in the source code, not an HTML comment. Does this exist?

To clarify on Joey's comment, that's actually something we're building into Edit Flow (the next feature, in fact):

The right side of this image works currently (i.e. description, due date, location, and workflow), but the left side of the image is something I'll be working on as soon as this website relaunch is up. Is that what you'd be looking for?