diff --git a/docs/deployment/topology-guide.md b/docs/deployment/topology-guide.md
index 1cfca789..84343034 100644
--- a/docs/deployment/topology-guide.md
+++ b/docs/deployment/topology-guide.md
@@ -151,7 +151,7 @@ Each site has its own two-node cluster:
 
 ### Site Cluster Behavior
 
-- Same split-brain resolver as central (keep-oldest).
+- Same split-brain resolver as central (`auto-down`, per the 2026-07-21 decision — see the Central Cluster Behavior note above).
 - Singleton actors: Site Deployment Manager migrates on failover.
 - Staggered instance startup: 50ms delay between Instance Actor creation to prevent reconnection storms.
 - SQLite persistence: each node owns its own consolidated LocalDb database, kept in step by