I guess you mean this document?
https://github.com/vapor/vapor/blob/a7f340f64b7182e9e4202a9b...
The only bit I see about tone is
“Communicating in a ‘tone’ you don’t find congenial” on a list of things they said they would NOT act on complaints about.
I see nothing in there that isn’t obvious getting-along-with-others stuff. It still seems to me that it’s helpful to write those things out rather than have them unspoken. It would feel unjust and arbitrary to me if I was pushed out of a community for bad behavior but not pre-warned what was considered bad behavior. It would also feel unjust if i were to be pushed out of a community because people kept saying shitty stuff to me and I complained about the hostility and they said “we have no rules, so they didn’t break any, suck it up”.