- IsPublic now refuses every non-globally-reachable IPv4 special-purpose range (adds 192.0.0.0/24, TEST-NET-1/2/3, 192.88.99.0/24, benchmarking 198.18.0.0/15) and admits IPv6 only from global unicast 2000::/3, minus its documentation, 6to4, Teredo and IETF protocol-assignment ranges. Test fixtures move off TEST-NET-3 to public addresses; Fetch-level tests cover the new blocked ranges and the public IPv6 path. - The cache stores and returns copies of Page.Body, so callers cannot alter cached bytes or race with other readers. - The per-host rate limiter advances only when a request is let through; a wait that ends with its context holds no slot. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>