diff -r 03d703c3cfe9 -r b5c32391802f make/uwproj.xsd
--- a/make/uwproj.xsd	Fri Nov 28 15:23:40 2025 +0100
+++ b/make/uwproj.xsd	Sun Nov 30 13:29:07 2025 +0100
@@ -29,23 +29,61 @@
             <xs:documentation>
                 <p>
                     The configuration section.
-                    Consists of an arbitrary number of <code>var</code> elements.
+                    Consists of an arbitrary number of <code>var</code> elements and pre-defined elements for
+                    standard installation directories. If you want to use standard installation directories, you
+                    must list the wanted variables here.
                 </p>
                 <p>
                     The optional <code>platform</code> attribute may specify a <em>single</em> platform identifier and
                     the optional <code>not</code> attribute may specify a comma-separated list of platform identifiers.
                     The configure script shall skip this config declaration if the detected platform is not matching
                     the filter specification of these attributes.
+                    When multiple config sections have a matching filter, and declare the same variables, the settings
+                    of the first matching config section will be used for the affected variables.
                 </p>
             </xs:documentation>
         </xs:annotation>
         <xs:sequence>
+            <xs:element name="prefix" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="exec-prefix" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="bindir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="sbindir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="libdir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="libexecdir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="datarootdir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="datadir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="sysconfdir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="sharedstatedir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="localstatedir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="runstatedir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="includedir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="infodir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="localedir" type="StandardConfigVarType" minOccurs="0"/>
+            <xs:element name="mandir" type="StandardConfigVarType" minOccurs="0"/>
             <xs:element name="var" type="ConfigVarType" minOccurs="0" maxOccurs="unbounded"/>
         </xs:sequence>
         <xs:attribute name="platform" type="xs:string"/>
         <xs:attribute name="not" type="xs:string"/>
     </xs:complexType>
 
+    <xs:complexType name="StandardConfigVarType">
+        <xs:annotation>
+            <xs:documentation>
+                The definition of a standard configuration variable.
+                <p>
+                    You may customize the value and the help text,
+                    but the variable name and the option name are pre-defined.
+                </p>
+            </xs:documentation>
+        </xs:annotation>
+        <xs:simpleContent>
+            <xs:extension base="xs:string">
+                <xs:attribute name="option-help" type="xs:string"/>
+                <xs:attribute name="exec" type="xs:boolean" default="false"/>
+            </xs:extension>
+        </xs:simpleContent>
+    </xs:complexType>
+
     <xs:complexType name="ConfigVarType">
         <xs:annotation>
             <xs:documentation>
@@ -55,14 +93,23 @@
                     written to the resulting config file (in contrast to make variables, which are only
                     written to the config file).
                     The <code>name</code> attribute is mandatory, the value is defined by the text body of the element.
-                    The optional Boolean <code>exec</code> attribute (false by default) controls, whether the entire
-                    definition is automatically executed under command substitution.
+                    The optional Boolean <code>exec</code> attribute (false by default) controls, whether value denotes
+                    a command which shall be executed at configuration time to produce the value.
+                    With <code>option</code> and <code>option-help</code> you can control how the variable can be
+                    overridden on the command line. When you don't specify either of those attributes, no command
+                    line option will be generated. When you provide a <code>option-help</code>, but do not specify the
+                    <code>option</code> name, a name is generated.
+                    You can use the string <code>%default</code> in your help text when you want to show the default
+                    value in the text. When <code>exec</code> is used, the default will not be resolved in the help
+                    text and instead the command is shown (to avoid breaking the formatting).
                 </p>
             </xs:documentation>
         </xs:annotation>
         <xs:simpleContent>
             <xs:extension base="xs:string">
                 <xs:attribute name="name" type="xs:string" use="required"/>
+                <xs:attribute name="option" type="xs:string"/>
+                <xs:attribute name="option-help" type="xs:string"/>
                 <xs:attribute name="exec" type="xs:boolean" default="false"/>
             </xs:extension>
         </xs:simpleContent>