I've seen LLMs causing three main issues for our community:

* Polished technical products no longer indicate effort and understanding.
* Making code easier to write exacerbates our existing issues with review bandwidth.
* People mechanically copy-pasting to and from an LLM is a waste of our time.

As time went on, these issues grew and grew, until we had to create dedicated channels and moderation policy for how to deal with them. However, those channels work against our goals of being transparent and welcoming, because new contributors have no idea what the rules are.

The new policy formalizes those rules publicly, so that new contributors know how to join our community without getting their PRs closed for reasons they don't understand, and so that existing reviewers can easily point to the rules as an actionable reason when closing PRs that don't follow them.

pub mod foo {
    pub mod bar {
        pub(crate) impl(super) trait Foo {}
    }

    // `Foo` may be implemented here.
    impl bar::Foo for i8 {}
}

// Error: `Foo` cannot be implemented here.
impl foo::bar::Foo for u8 {}

pub mod foo {
    pub struct Bar {
        pub mut(self) alpha: &'static str,
    }

    impl Bar {
        pub fn mutate_inner(&mut self) {
            // `alpha` may be mutated here.
            self.alpha = "inner";
        }
    }
}

impl foo::Bar {
    pub fn mutate_outer(&mut self) {
        // Error: `alpha` cannot be mutated here.
        self.alpha = "outer";
    }
}