I was thinking the other day how cool it'd be to be able to hide so-called "metadata" inside otherwise "publicly visible" content, perhaps explaining how/why something was worded or formatted a certain way, or to embed hidden requests for grammatical improvement, etc.
These could then be taken into account by other editors, and it would make altering other people's posts a much less tense/stressful experience in certain circumstances.
EDIT: I see it's possible to use HTML comments to achieve this, so now my question is, can the use of HTML comments to embed information to/for other editors be popularized/encouraged? I can see it now... a dedicated tab, perhaps titled "Meta", which would tell everyone about the option: