diff --git a/homelab-overview.md b/homelab-overview.md
index 3742efd..3fe5df1 100644
--- a/homelab-overview.md
+++ b/homelab-overview.md
@@ -105,6 +105,18 @@ Internet
 [WireGuard (107)] — VPN access to homelab
 ```
 
+---
+## DNS architecture (updated 2026-08-10)
+All spendlik.sk subdomains are CNAME records pointing at the root:
+  *.spendlik.sk, git, mcp, vault, automation, matrix, email, auth, books, jellyfin, paperless
+  → CNAME → spendlik.sk
+
+Only spendlik.sk (record id 12631197, A record) holds an IP. ddns-update.sh on CT 108
+updates only this record on IP change; CNAMEs resolve through automatically.
+
+Do NOT add per-subdomain A records — WebSupport rejects duplicate IP values zone-wide
+(see 00_index.md gotchas).
+
 ---
 
 ## Claude AI Integration