Sadly these guidelines are as incoherent as last time. For example, the rules absolutely forbid using an `unsafe` block to call a rust function (since this fall

Sadly these guidelines are as incoherent as last time. For example, the rules absolutely forbid using an `unsafe` block to call a rust function (since this falls in none of the allowed uses of `unsafe`), but then the rules turn around and require the use of `unsafe` to zero out variables.