diff --git a/include/client.h b/include/client.h
index 8df9431d..ba890b57 100644
--- a/include/client.h
+++ b/include/client.h
@@ -438,6 +438,7 @@ struct ListClient
 #define LFLAGS_CORK		0x00000004
 #define LFLAGS_SCTP		0x00000008
 #define LFLAGS_SECURE		0x00000010	/* for marking SSL clients as secure before registration */
+/* LFLAGS_FAKE: client may not have the usually expected machinery plugged in; don't assert on it. For tests only. */
 #define LFLAGS_FAKE		0x00000020
 
 /* umodes, settable flags */