Could be wrong though, just writing this from memory.
Only users with 500 karma can downvote.
Both are mechanisms to dull the potency of new users until they have a chance to learn how HN is expected to work.
This might sound gatekeeping, and it literally is, but consider than HN signup is open and takes 15 seconds with no verification. HN likes the way HN works and these provide simple rate-limits on destructive or oblivious change.
That term presumes unkept gates are preferable.
I grew up farming. One keeps one's gates or both wildlife and livestock run amuck.
It made sense to me almost immediately, so since people aren't making the connection: https://www.oxfordlearnersdictionaries.com/us/definition/eng...
>5 (informal) (of a person) young and without experience
> The new trainees are still very green.
YCombinator founders have their own colours which are only visible to each other.
There are plenty of undocumented features like this one.