There are a few attributes that are currently not documented. I wanted to get feedback if these should be documented. I've included my inclination, but I'd like to hear what others think.

• automatically_derived — I vote "probably"? It has some use in the wild. I think the only reason to use it is for rustdoc. Are there other reasons to use it?
• feature — I vote "maybe" 🤔? Although this is a nightly-oriented attribute, it is very widely used.
• type_length_limit — I vote "yes". I think it is analogous to recursion_limit, and I suspect it just fell through the cracks.
• bench — I vote "no". It requires the unstable Bencher to be used. (Now destabilized via Remove derives Encodable/Decodable and unstabilize attribute #[bench] rust#62507)
• reexport_test_harness_main — I vote "no". Even though it is usable on stable, I think it is an internal implementation detail, and I do not see anyone using it.

These are just waiting to be finished:

• panic_handler (document #[panic_handler] #362)
• used (document #[used] #361)
• target_feature (target_feature (RFC 2045, RFC 2325) #286)