diff --git a/content/(reference)/limits.mdx b/content/(reference)/limits.mdx
index 19d8d89..089ede3 100644
--- a/content/(reference)/limits.mdx
+++ b/content/(reference)/limits.mdx
@@ -99,11 +99,11 @@ A space that stops serving does not fall back to a blank 404. The status code an
 | Account suspended | `402` | `This space is paused.` | `403` `tenant_suspended` |
 | Space disabled, expired, or taken down | `404` | `This space is no longer available.` | `409` with the disable reason |
 | Removed after a legal complaint | `451` | `This content is unavailable for legal reasons.` | `409` |
-| Removed under the strictest safety category | `503` | `This space hasn't been published yet.` | `409` |
+| Removed under the strictest safety category | `404` | `This space hasn't been published yet.` | `409` |
 
 Reads are never blocked by account state. Only writes are. A past-due account keeps serving every site at full speed for the whole grace period, and only the dashboard, CLI, and API stop accepting changes.
 
-The 451 and 404 pages are customizable like any other error page. The 503 case is byte-identical to a host that has never published anything.
+The legal-removal and no-longer-available pages are customizable like any other error page. The strictest-safety response is byte-identical to a host that has never published anything. The strictest-safety response and a never-published host both return `404` with `X-Spacefast-Undeployed: 1` and the unpublished body, which distinguish them from a missing page on a published site.
 
 ## Rate limits
 
diff --git a/content/(serve)/urls.mdx b/content/(serve)/urls.mdx
index 179859d..b6010f5 100644
--- a/content/(serve)/urls.mdx
+++ b/content/(serve)/urls.mdx
@@ -94,4 +94,4 @@ Any hostname ending in `.space.fast` or `.view.fast` is refused as a custom doma
 
 ## Hostnames that do not serve
 
-A request to a hostname Spacefast does not route, or to a Space that has never published, answers `503` with `Cache-Control: no-store` and the body `This space hasn't been published yet.` It is deliberately not a 404, so a monitoring check can tell "nothing here yet" apart from "this page is missing".
+A request to a hostname Spacefast does not route, or to a Space that has never published, answers `404` with `Cache-Control: no-store` and the body `This space hasn't been published yet.` The response includes `X-Spacefast-Undeployed: 1`. Use that header or the body to tell "nothing here yet" apart from a missing page on a published site.