This prevents rustdoc from inlining docs from another crate's constant items. example code: ``` rust // foo.rs #![crate_type="lib"] /// Docs for a const pub const FOO: &'static str = "Foo bar"; ``` ``` rust // bar.rs #![crate_type="lib"] extern crate foo; pub use foo::FOO; ``` (This issue is unrelated to the myriad issues rustdoc currently has with constants, and came up while I was fixing them).