diff --git a/src/lang/ido.txt b/src/lang/ido.txt
--- a/src/lang/ido.txt
+++ b/src/lang/ido.txt
@@ -906,6 +906,8 @@ STR_NETWORK_SERVER_MESSAGE              
 
 # Linkgraph legend window and linkgraph legend in smallmap
 
+# Linkgraph tooltip
+
 # Base for station construction window(s)
 STR_STATION_BUILD_ACCEPTS_CARGO                                 :{BLACK}Aceptas: {GOLD}{CARGO_LIST}