When I see just a simple `TODO` in some OSS project it's often hard to understand either it's a broken edge case or some micro optimization or refactoring left for future. For my projects I adopted (it grew naturally) priority tags, e.g. `TODO!!! [(WTF)]` for critical [tricky/edge case] bugs, `TODO!` for important hot paths optimizations, `TODO (low)` for nice to have, `TODO?` or `TODO (review)` for rethinking design later.

Actual tags are not as important as ability to understand the priority at a glance without looking up a tag in some docs. And fixing all `TODO!*`s is high priority, ideally they should not be committed.