patch 7.4.775
Problem:    It is not possible to avoid using the first item of completion.
Solution:   Add the "noinsert" and "noselect" values to 'completeopt'. (Shougo
            Matsu)
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 320b154..e371a74 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1819,6 +1819,14 @@
 		    completion in the preview window.  Only works in
 		    combination with "menu" or "menuone".
 
+	   noinsert Do not insert any text for a match until the user selects
+		    a match from the menu. Only works in combination with
+		    "menu" or "menuone". No effect if "longest" is present.
+
+	   noselect Do not select a match in the menu, force the user to
+		    select one from the menu. Only works in combination with
+		    "menu" or "menuone".
+
 
 						*'concealcursor'* *'cocu'*
 'concealcursor' 'cocu'	string (default: "")