To me, FIX implies that something is wrong, not that it works but could use improvement.

I would like to have a tag for "here's something that works, but could be improved" though!

That seems like a good compromise. I've used LOOKAT to note places where I got things going but felt like there was a better way of doing things if I had more time.

Is there a standard for valid flags? I recently recommended a client use `TODOSECURITY` for todos which had security implications until fixed - I discovered functionality which was implemented before authorisation had been developed, resulting in a codepath which was unintentionally reachable by standard users.

Seemed weird to make up a codeword but I wasn't aware of any standard convention, and visually highlighting high impact issues (w/ the bonus of greppability) seemed like a sane approach in rapid development environments.