diff --git a/ADQL.tex b/ADQL.tex
index 9e16ded..1caccdf 100644
--- a/ADQL.tex
+++ b/ADQL.tex
@@ -2512,9 +2512,9 @@ \subsubsection{Overview}
     gavo_convert()
 \end{verbatim}
 
-The \verb:ivo: prefix is reserved for functions that have been defined
-in an IVOA specification. For example the \RegTAPSpec{} defines the following
-functions:
+The \verb:ivo: prefix is reserved for functions that have been defined in an
+IVOA specification or Endorsed Note. For example the \CatalogueUDF{} defines the
+following functions:
 \begin{verbatim}
     ivo_nocasematch()
     ivo_hasword()