2026-09-27 17:06:40 +00:00
2 changed files with 11 additions and 2 deletions
@@ -149,6 +149,15 @@ moves that to a host port requirement.

 ## A seat that delivers nothing

+**A module's declared seat may promise nothing too, and that is a marker seat.** Correction of fact,
+2026-09-27: [ADR 0126](../../02-DECISIONS/0126-a-module-declares-its-own-seats.md)'s "a declared seat
+carries a protocol" governs what a *holder* must satisfy, not that every seat offers something. A
+marker seat's protocol is satisfied by holding it, which is the whole of what a marker says. Refusing
+an empty one would refuse most of the node-scoped set, the showcase module's own seat included.
+Nothing reaches that state by accident: an unknown manifest field is refused outright, so an empty
+protocol was written as one. Checked by a registration test accepting a node seat with no protocol
+and by the showcase manifest, which declares one.
+
 Most node seats deliver nothing. They say which module is this machine's packet filter, or which of
 two alternative resolver configurations it runs, and a second holder is refused. That is the whole of
 their job, and it is a real one: it is the mesh saying what a machine is, in words a person can read.
@@ -193,7 +202,7 @@ checked as their tables say:

 | Rule | Checked by |
 |---|---|
-| The set is closed, and every mesh entry names its decision | 0118: a unit test on the mesh's own entries; manifest tests refusing an unknown seat or the wrong scope. |
+| The set is closed, and every mesh entry names its decision | 0118: a unit test on the mesh's own entries. **The refusal of an unknown seat is at registration, not in the parser** — correction of fact, 2026-09-27: a module may hold a seat *another* module declares, which is the point of naming the seat and not its provider, so whether a claimed name exists is a fact about the whole catalogue and a manifest in isolation cannot be judged on it. Registration tests cover an invented name and a name another module declares; the parser still refuses a claim on the mesh's own `mesh-*`/`node-*` namespace and a scope that disagrees with a declaration in the same manifest. |
 | The set is derived, and enumerating it is a query | 0118: the overview lists the mesh's own plus every registered module's, asserted against a fixture mesh. |
 | `mesh-*` is the mesh's, and a module may not declare one | 0118: a registration test refusing a manifest that declares any `mesh-*` seat, naming the prefix. |
 | Two modules cannot declare the same seat | 0118: a registration test; the second is refused and the first untouched. |
@@ -1,5 +1,5 @@
 ---
-status: fixed
+status: resolved
 opened: 2026-09-24
 located-in: [mesh-controller internal/inventory, mesh-controller internal/catalogue, mesh-controller cmd/mesh-controller, mesh-catalog modules/dnsmasq]
 fixed-by: [mesh-controller#73 overlay-name + namesInTheMesh, mesh-catalog#106 dnsmasq daemon.json merge]