These are the extensions mentioned on the Web :)

Change-Id: I1af6d1ed6b62611ff931f8b0dfa6409d73242fc9

filter/source/config/fragments/types/writer_WriteNow.xcu

@@ -18,7 +18,7 @@
     <node oor:name="writer_WriteNow" oor:op="replace" >
         <prop oor:name="DetectService"><value>com.sun.star.comp.Writer.MWAWImportFilter</value></prop>
         <prop oor:name="URLPattern"/>
-        <prop oor:name="Extensions"><value>dummy</value></prop>
+        <prop oor:name="Extensions"><value>wn nx^d</value></prop>
         <prop oor:name="MediaType"><value></value></prop>
         <prop oor:name="Preferred"><value>true</value></prop>
         <prop oor:name="PreferredFilter"><value>WriteNow</value></prop>