I recently created a new tag called nano (the inverse of giga, related to micro and macro). This isn't a proposal, it's already done, I just wanted to share its existence with other members so that people are aware of its existence and tag it on future relevant posts.

https://e621.net/wiki_pages/31646

https://e621.net/posts?tags=nano

I spent a few hours digging around with some posts and artists I thought could qualify for this tag and managed to tag almost a hundred posts, but there are probably a ton more posts that could qualify for this tag that aren't tagged yet.