diff --git a/StructFields.pm b/StructFields.pm
index e2ae40d7f..0a168a456 100644
--- a/StructFields.pm
+++ b/StructFields.pm
@@ -753,7 +753,7 @@ sub emit_struct_fields($$;%) {
                 emit $_ for @ctor_lines;
             };
         }
-    } 'ctors';
+    } 'ctors' unless $flags{-noconstructor};
 
     %info = $flags{-addmethods}->($tag) if $flags{-addmethods};
 
@@ -785,7 +785,7 @@ sub emit_struct_fields($$;%) {
                     ($inherits ? "&${inherits}::_identity" : 'NULL'), ', ',
                     "${ftable}${maybe_index_enum});";
         }
-    } 'fields-' . $fields_group;
+    } 'fields-' . $fields_group unless $flags{-noidentity};
 }
 
 for my $letter ('a' .. 'z') {
diff --git a/StructType.pm b/StructType.pm
index d9cfe1d00..b1305b641 100644
--- a/StructType.pm
+++ b/StructType.pm
@@ -227,6 +227,20 @@ sub render_struct_type {
 
     my $ispec = '';
 
+    my $using = '';
+    my $noidentity = 0;
+    my $noctor = 0;
+
+    if (@codegen_override) {
+        $using = $codegen_override[0]->getAttribute('using');
+        $noidentity = $codegen_override[0]->getAttribute('no-identity');
+        $noctor = $codegen_override[0]->getAttribute('no-constructor');
+        my $template = $codegen_override[0]->getAttribute('template');
+        if ($template) {
+            $using = "$template<$using>";
+        }
+    }
+
     for my $extra ($tag->findnodes('extra-include')) {
         my $tname = $extra->getAttribute('type-name');
         if ($tname) {
@@ -311,7 +325,7 @@ sub render_struct_type {
             };
 
             emit_struct_fields($tag, $typename, -class => $is_class, -inherits => $inherits,
-                                -addmethods => $vmethod_emit);
+                                -addmethods => $vmethod_emit, -noidentity => $noidentity, -noctor => $noctor);
 
             if ($field_backrefs{$typename}) {
                 for my $backref (@{$field_backrefs{$typename}}) {
@@ -323,12 +337,9 @@ sub render_struct_type {
         } $tag, "$typename$ispec", -export => 1;
     };
 
-    if (@codegen_override) {
-        my $using = $codegen_override[0]->getAttribute('using');
-        if ($using) {
-            emit "using $typename = $using;";
-            return;
-        }
+    if ($using) {
+        emit "using $typename = $using;";
+        return;
     }
 
     emit $_ for @struct;
diff --git a/data-definition.xsd b/data-definition.xsd
index 0870d720b..2d85d2a9f 100644
--- a/data-definition.xsd
+++ b/data-definition.xsd
@@ -17,8 +17,10 @@
                 <xs:complexType>
                     <xs:simpleContent>
                         <xs:extension base="xs:string">
-                            <xs:attribute name="using" use="required">
-                            </xs:attribute>
+                            <xs:attribute name="using" use="optional" type="xs:string"/>
+                            <xs:attribute name="template" use="optional" type="xs:string"/>
+                            <xs:attribute name="no-identity" use="optional" type="xs:boolean" default="false"/>
+                            <xs:attribute name="no-constructor" use="optional" type="xs:boolean" default="false"/>
                         </xs:extension>
                     </xs:simpleContent>
                 </xs:complexType>