diff --git a/Manuals/Docbook/Licenses/Gfdl/section-1.docbook b/Manuals/Docbook/Licenses/Gfdl/section-1.docbook
index eb29bbf..1ae7752 100644
--- a/Manuals/Docbook/Licenses/Gfdl/section-1.docbook
+++ b/Manuals/Docbook/Licenses/Gfdl/section-1.docbook
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<section>
+<section id="licenses-gfdl-section-1" xreflabel="Preamble">
 
     <title>Preamble</title>