Constant REPLAY_RANGE_ADVICE 

pub const REPLAY_RANGE_ADVICE: &str = "replayed state is resolved by the recording that begins \
     where the request does, so request a range that begins where one was recorded and ends \
     within it";

Why a replayed range has to begin where a recording does. Shared so the splitter’s refusal and the service’s single-session refusal cannot drift apart.