I think it would be important to include in this pledge:
* Transitive closure rule. (No external dependencies not covered by the pledge. Possibly with certain exceptions e.g. for bindings to big known obvious third party dependencies like SQL databases or Operating Systems.)
* Uniform licensing rule. (Everything must use the exact same license, with a single group name as copyright holders and for any purposes of required notices etc.)
* Maintenance, backward compatibility and platform compatibility rule. (100% compatibility forever everywhere is not even necessary, but an _explicit_ rule of thumb of what reasonable time frames for deprecation windows and recommended transition plans can be expected would be nice.)
Or maybe this already exists and I'm just uninformed?
That person isn't random; they're on the libs team and the primary author of regex. (there are a few crates by other people as well, but most of those crates were extracted from regex as they can be useful on their own.)