Add "t" option to 'complete'. Visually it looks odd, that the icons are

more indented than others, we might want to remove or at least move the
% and # indicators

common/content/liberator.js

@@ -1491,7 +1491,20 @@ const liberator = (function () //{{{
             // convert the string to an array of converted URLs
             // -> see util.stringToURLArray for more details
             if (typeof urls == "string")
+            {
+                // rather switch to the tab instead of opening a new url in case of "12: Tab Title" like "urls"
+                if (liberator.has("tabs"))
+                {
+                    let matches = urls.match(/^(\d+):/);
+                    if (matches)
+                    {
+                        tabs.select(parseInt(matches[1], 10) - 1, false); // make it zero-based
+                        return;
+                    }
+                }
+
                 urls = util.stringToURLArray(urls);
+            }
 
             if (urls.length > 20 && !force)
             {

common/content/tabs.js

@@ -645,6 +645,10 @@ function Tabs() //{{{
             { argCount: "0" });
     }
 
+    completion.addUrlCompleter("t",
+        "Open tabs",
+        completion.buffer);
+
     /////////////////////////////////////////////////////////////////////////////}}}
     ////////////////////// PUBLIC SECTION //////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{

common/content/ui.js

@@ -770,7 +770,7 @@ function CommandLine() //{{{
 
     options.add(["complete", "cpt"],
         "Items which are completed at the :open prompts",
-        "charlist", "slf",
+        "charlist", typeof(config.defaults["complete"]) == "string" ? config.defaults["complete"] : "slf",
         {
             completer: function (context) [k for each (k in completion.urlCompleters)],
             validator: Option.validateCompleter