diff -r -u freeciv-1.7.2-base/client/diplodlg.c freeciv-1.7.2/client/diplodlg.c
--- freeciv-1.7.2-base/client/diplodlg.c	Fri Jan 15 12:49:50 1999
+++ freeciv-1.7.2/client/diplodlg.c	Fri Jan 15 12:50:15 1999
@@ -40,6 +40,7 @@
 #include <map.h>
 #include <xstuff.h>
 #include <chatline.h>
+#include <capability.h>
 
 extern Widget toplevel;
 
@@ -273,6 +274,7 @@
   char buf[512], *pheadlinem;
   struct Diplomacy_dialog *pdialog;
   Dimension width, height, maxwidth;
+  int tradecities = FALSE;
   Widget popupmenu;
   Widget entry;
   XtTranslations textfieldtranslations;
@@ -380,6 +382,13 @@
 
   /* Start of trade city code - Kris Bubendorfer */
 
+  
+  if(has_capability("tradecities", aconnection.capability) 
+     && has_capability("tradecities", plr0->conn->capability) 
+     && has_capability("tradecities", plr1->conn->capability))
+    tradecities = TRUE;
+
+     
   pdialog->dip_city_menubutton0=XtVaCreateManagedWidget("dipcitymenubutton0", 
 							menuButtonWidgetClass,
 							pdialog->dip_form0,
@@ -388,9 +397,10 @@
 				 simpleMenuWidgetClass, 
 				 pdialog->dip_city_menubutton0, 
 				 NULL);
-
+  
+  
   fill_diplomacy_city_menu(popupmenu, plr0, plr1);
-  XtSetSensitive(pdialog->dip_city_menubutton0, TRUE);
+  XtSetSensitive(pdialog->dip_city_menubutton0, tradecities);
   
   
   pdialog->dip_city_menubutton1=XtVaCreateManagedWidget("dipcitymenubutton1", 
@@ -401,9 +411,10 @@
 				 simpleMenuWidgetClass, 
 				 pdialog->dip_city_menubutton1, 
 				 NULL);
+  
   fill_diplomacy_city_menu(popupmenu, plr1, plr0);
-  XtSetSensitive(pdialog->dip_city_menubutton1, TRUE);
-
+  XtSetSensitive(pdialog->dip_city_menubutton1, tradecities);  
+  
   /* End of trade city code */
   
   pdialog->dip_gold_input0=XtVaCreateManagedWidget("dipgoldinput0", 
Only in freeciv-1.7.2/common: packets.h~
diff -r -u freeciv-1.7.2-base/common/shared.h freeciv-1.7.2/common/shared.h
--- freeciv-1.7.2-base/common/shared.h	Fri Jan 15 12:49:46 1999
+++ freeciv-1.7.2/common/shared.h	Fri Jan 15 12:55:45 1999
@@ -70,7 +70,7 @@
  */
 
 /* The default string is really simple */
-#define CAPABILITY "+1.7 clientcapabilities"
+#define CAPABILITY "+1.7 clientcapabilities tradecities"
 
 #define CITY_NAMES_FONT "10x20"
 #define BROADCAST_EVENT -2