From 67848096d1dee5d02b0e5cb56ccaa329ccf3124d Mon Sep 17 00:00:00 2001 From: Joost de Valk Date: Mon, 7 Sep 2026 08:12:24 +0200 Subject: [PATCH] add(considered): RFC 10036 Incremental is registered, not deployed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Incremental header is in scope — origin-set, on the wire, with an outcome a visitor feels — but it was published a month ago and nothing we can find reads it yet. Record the turn-down with what would reverse it. Co-Authored-By: Claude Opus 5 (1M context) --- .../considered/incremental-forwarding.md | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 src/content/considered/incremental-forwarding.md diff --git a/src/content/considered/incremental-forwarding.md b/src/content/considered/incremental-forwarding.md new file mode 100644 index 00000000..ad57d9fb --- /dev/null +++ b/src/content/considered/incremental-forwarding.md @@ -0,0 +1,19 @@ +--- +title: "Incremental forwarding of HTTP messages (RFC 10036)" +date: "2026-09-07" +reason: too-early +revisit: "An intermediary honouring the field — a CDN documenting it, or h2o or nginx shipping support. Given that one of the authors works on h2o at Fastly, an h2o release note would be the earliest credible signal." +sources: + - title: "RFC 10036 — Incremental Forwarding of HTTP Messages" + url: "https://www.rfc-editor.org/rfc/rfc10036.html" + publisher: "IETF" + - title: "IANA — HTTP Field Name Registry" + url: "https://www.iana.org/assignments/http-fields/http-fields.xhtml" + publisher: "IANA" +--- + +RFC 10036 registers one response and request header, `Incremental`, a Structured Fields boolean. `Incremental: ?1` tells every intermediary in the chain not to buffer the whole message before forwarding it. It fills a real gap: HTTP has never had a way for an origin to say "this body is meant to be consumed as it arrives", so proxies and CDNs decide by sniffing `Content-Type` or by vendor-specific configuration. Anything streamed — server-sent events, a progressively rendered response, a long-running tool call — is at the mercy of whatever heuristic sits in front of it. + +It also clears the scope bar comfortably, which is why it is worth recording rather than dismissing. The field is set by the origin, it is visible on the wire, and the outcome is one a visitor feels directly: content that appears as it is generated instead of arriving in one lump at the end. + +The problem is that it was published in August 2026 and nothing appears to read it yet. There is no MDN page or Browser Compatibility Data key, no Chrome Platform Status entry, and no mention in the CDN documentation or changelogs we checked. That is unsurprising a month after publication, and the RFC itself anticipates a transition period in which unaware intermediaries simply ignore the field — but it means a page today would recommend setting a header that changes nothing on any reader's path. The standard is not the problem; the deployment has not started.