diff --git a/tailcfg/tailcfg.go b/tailcfg/tailcfg.go
index e4a16176b..ea3055285 100644
--- a/tailcfg/tailcfg.go
+++ b/tailcfg/tailcfg.go
@@ -512,6 +512,8 @@ type MapRequest struct {
 	//       router but their IP forwarding is broken.
 	//     * "v6-overlay": IPv6 development flag to have control send
 	//       v6 node addrs
+	//     * "minimize-netmap": have control minimize the netmap, removing
+	//       peers that are unreachable per ACLS.
 	DebugFlags []string `json:",omitempty"`
 }