I think it makes sense to refine the levels a bit more. We use FIXME, TODO and OPTIMIZE in order of decreasing importance.

- FIXME should really not even be committed, except in a proof of concept

- TODO should be fixed eventually, preferably before release to production

- OPTIMIZE is a "nice to have" that gets fixed on a quiet day

Furthermore, TBD (to be done) indicates where new expected functionality is expected to appear, deliberately different from TODO because the JetBrains editor flags TODO / FIXME for confirmation before commit, and will ignore TBD.