venues get a document, written from entry 6

Four documents used the word and none defined it. cart.md leaned on it hardest —
an authority claim entering as a venue fact carries a reason and can be shown
wrong — which is a real mechanism resting on an undefined term.

It is bedrock's because venues/ is one of the directories starting.md already
lists beside published/ and gaps/. A concept named in the primitives was being
half-defined in a downstream convention's four-line aside, which is the same
diagnosis loom-cli made about publication two days ago. Second instance of that
shape.

Nothing is invented: entry 6 settled this on 2026-09-05 and the table is that
entry's. New here is that a venue file is local because it has no upstream, and
that it goes stale in a way no fetch can detect — so it needs the reason
underneath the choice or it cannot be checked at all.

Entry 84.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.loom/published/venues.md

@@ -0,0 +1,81 @@
+# Venues
+
+**`.loom/venues/<name>.md` — a choice you made about something that has no
+document of its own to hang it on.**
+
+*Kafka. React. HTTP. The organisation you work for.* **Things that constrain what
+you build without ever being invoked, and without publishing anything at you that
+you could adopt.**
+
+---
+
+## Venue and external are two questions, not two kinds of thing
+
+**`external` is *who published it*. `venue` is *whether you had to decide
+anything about it*.** *They are orthogonal. A thing may be both, either, or
+neither.*
+
+| | published at us | we recorded a choice | files |
+|---|---|---|---|
+| Kafka, React, HTTP | yes, by the world | yes — *protobuf for schema* | venue only |
+| a service another team owns | yes, by them | not yet — the use is in the code | external only |
+| a cluster your own org publishes | yes | yes | both |
+| a library you use exactly as documented | yes | no | neither |
+
+**Both files are governed by the same rule, applied to two different ambients:**
+
+> **An external entry exists when the reader cannot be assumed to know the
+> thing.** *A venue file exists when you made a choice worth recording.*
+
+**Nobody needs telling what Kafka is, so there is no external entry** — *but "we
+use protobuf for schema" is a choice, so there is a venue file.* **Nobody outside
+can know what your internal API is for, so there is an external entry** — *and
+until using it requires an exception or a preference, there is nothing to
+accommodate and no venue file, because the actual use is in the code.*
+
+*This is why sorting things into two bins does not work and people keep trying.
+The bins were never the problem. The question was.*
+
+## A venue file is an account of your own decisions
+
+**Which is what makes it local by construction.** *An external is a copy of
+somebody's document and could in principle be centralised.* **A venue file has no
+upstream** — *there is nobody to reconcile with, because the only party who
+decided anything was you.*
+
+**So it does not go stale the way a copy does.** *It goes stale when you change
+your mind and do not say so*, which no fetch will ever detect.
+
+> **A venue file that carries no delta should not exist.** *If you use the thing
+> exactly as documented, write nothing.* **Recording the adoption is ceremony.**
+
+## If there is a document, hang the choice on the document
+
+**Put a choice where reconciliation will look for it.** *When the thing you
+decided about publishes something you have adopted, the choice belongs in the
+`.usages.md` beside that copy and not in a venue file* — **because that is the
+file somebody opens when the document moves**, *and a venue file is not.*
+
+*The venue file is for what is left: the constraints of a thing that publishes
+nothing you can hold.*
+
+## A venue is where an authority claim belongs
+
+**Because a venue fact carries a reason and can therefore be shown wrong.**
+
+*The alternative is worse and common: somebody with authority enters a
+conversation as a voice, and "we do it this way" arrives with no reason attached
+and nothing that could contradict it.* **Written as a venue constraint, the same
+instruction becomes a claim about the world**, *and a claim about the world is
+something a later reader can discover was false.*
+
+## Checking it is still true
+
+**Nobody will tell you.** *There is no publisher to ask, no `ETag`, and no
+conditional request that will ever come back `200`.*
+
+**So a venue file needs what a published document needs: a date, and the reason
+underneath the choice.** *The reason is the whole of it* — **"we use protobuf for
+schema" is unfalsifiable a year later; "we use protobuf because the consumers are
+in three languages and JSON schema drift was costing us a release a quarter" can
+be checked against a world that may have changed.**