--- broker.original
+++ M08-unknown
@@ -6454,7 +6454,6 @@
           const selected = new Set();
           for (const tag of addressed.tags) {
             const candidates = new Set([this.#named(s.business, tag), tag].filter((instance) => members.includes(instance)));
-            if (!candidates.size) fail('unknown-addressee');
             if (candidates.size > 1) fail('addressee-ambiguous');
             selected.add([...candidates][0]);
           }