Index: trunk/data/defaultpresets.xml
===================================================================
--- trunk/data/defaultpresets.xml	(revision 7164)
+++ trunk/data/defaultpresets.xml	(revision 7171)
@@ -118,4 +118,5 @@
   value_on: the value to set when checked (default is "yes")
   value_off: the value to set when unchecked (default is "no")
+  disable_off: whether the off value is disabled in the dialog, i.e., only unset or yes are provided
   match: none/key/key!/keyvalue (default is "none", see below for more information)
 
@@ -172,8 +173,8 @@
     </chunk>
     <chunk id="highway_yesno_incline">
-        <check key="bridge" text="Bridge" />
-        <check key="tunnel" text="Tunnel" />
-        <check key="cutting" text="Cutting" />
-        <check key="embankment" text="Embankment" />
+        <check key="bridge" text="Bridge" disable_off="true" />
+        <check key="tunnel" text="Tunnel" disable_off="true" />
+        <check key="cutting" text="Cutting" disable_off="true" />
+        <check key="embankment" text="Embankment" disable_off="true" />
         <combo key="incline" text="Incline" values="10%,-10%,10°,-10°,up,down"/>
     </chunk>
@@ -380,8 +381,8 @@
                 <checkgroup columns="4">
                     <check key="oneway" text="Oneway" default="on" />
-                    <check key="bridge" text="Bridge" />
-                    <check key="tunnel" text="Tunnel" />
-                    <check key="cutting" text="Cutting" />
-                    <check key="embankment" text="Embankment" />
+                    <check key="bridge" text="Bridge" disable_off="true" />
+                    <check key="tunnel" text="Tunnel" disable_off="true" />
+                    <check key="cutting" text="Cutting" disable_off="true" />
+                    <check key="embankment" text="Embankment" disable_off="true" />
                     <check key="lit" text="Lit" />
                     <check key="toll" text="Toll" />
@@ -404,8 +405,8 @@
                 <checkgroup columns="4">
                     <check key="oneway" text="Oneway" default="on" />
-                    <check key="bridge" text="Bridge" />
-                    <check key="tunnel" text="Tunnel" />
-                    <check key="cutting" text="Cutting" />
-                    <check key="embankment" text="Embankment" />
+                    <check key="bridge" text="Bridge" disable_off="true" />
+                    <check key="tunnel" text="Tunnel" disable_off="true" />
+                    <check key="cutting" text="Cutting" disable_off="true" />
+                    <check key="embankment" text="Embankment" disable_off="true" />
                     <check key="lit" text="Lit" />
                     <check key="toll" text="Toll" />
@@ -432,8 +433,8 @@
                     <check key="oneway" text="Oneway" default="on" />
                     <check key="motorroad" text="Motorroad" default="on" />
-                    <check key="bridge" text="Bridge" />
-                    <check key="tunnel" text="Tunnel" />
-                    <check key="cutting" text="Cutting" />
-                    <check key="embankment" text="Embankment" />
+                    <check key="bridge" text="Bridge" disable_off="true" />
+                    <check key="tunnel" text="Tunnel" disable_off="true" />
+                    <check key="cutting" text="Cutting" disable_off="true" />
+                    <check key="embankment" text="Embankment" disable_off="true" />
                     <check key="lit" text="Lit" />
                     <check key="toll" text="Toll" />
@@ -457,8 +458,8 @@
                     <check key="oneway" text="Oneway" default="on" />
                     <check key="motorroad" text="Motorroad" default="on" />
-                    <check key="bridge" text="Bridge" />
-                    <check key="tunnel" text="Tunnel" />
-                    <check key="cutting" text="Cutting" />
-                    <check key="embankment" text="Embankment" />
+                    <check key="bridge" text="Bridge" disable_off="true" />
+                    <check key="tunnel" text="Tunnel" disable_off="true" />
+                    <check key="cutting" text="Cutting" disable_off="true" />
+                    <check key="embankment" text="Embankment" disable_off="true" />
                     <check key="lit" text="Lit" />
                     <check key="toll" text="Toll" />
@@ -2630,6 +2631,6 @@
             <key key="public_transport" value="station" />
             <text key="name" text="Name" />
-            <check key="area" text="Area" />
-            <check key="building" text="Building" />
+            <check key="area" text="Area" disable_off="true" />
+            <check key="building" text="Building" disable_off="true" />
             <text key="operator" text="Operator" />
             <text key="network" text="Network" />
Index: trunk/data/tagging-preset.xsd
===================================================================
--- trunk/data/tagging-preset.xsd	(revision 7164)
+++ trunk/data/tagging-preset.xsd	(revision 7171)
@@ -247,4 +247,5 @@
 		<attribute name="value_on" type="string" />
 		<attribute name="value_off" type="string" />
+        <attribute name="disable_off" type="boolean" />
 		<attribute name="match" type="tns:match" />