Well, there's no spec for any part of the language, there's a bunch of non-normative documents about how rustc might happen to work. In the non-normative docume

Well, there's no spec for any part of the language, there's a bunch of non-normative documents about how rustc might happen to work. In the non-normative documents that speculate about what guarantees rustc might require of unsafe code in order to avoid undefined behavior and ensure memory safety, provenance certainly does come up.