diff --git a/lib/doc/Customization.lyx b/lib/doc/Customization.lyx
index 1f9e620c88..2dc75e6225 100644
--- a/lib/doc/Customization.lyx
+++ b/lib/doc/Customization.lyx
@@ -13967,29 +13967,29 @@ status collapsed
 
 \end_inset
 
- must be of the form 
-\begin_inset Flex Code
-status collapsed
-
-\begin_layout Plain Layout
-Flex:Identifier
-\end_layout
-
-\end_inset
-
-, where 
-\begin_inset Flex Code
-status collapsed
-
-\begin_layout Plain Layout
-Identifier
-\end_layout
-
-\end_inset
-
- is any valid identifier not used by a pre-existing inset.
- The identifier may include spaces, but the whole thing must in that case
+ may be be any valid identifier not used by a pre-existing inset.
+ The identifier may include spaces, but in that case the whole thing must
  be wrapped in quotes.
+ It may also include a namespace identifier, preceding a colon, such as
+ 
+\begin_inset Quotes eld
+\end_inset
+
+
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+Flex:Code
+\end_layout
+
+\end_inset
+
+
+\begin_inset Quotes erd
+\end_inset
+
+.
  Note that the definition of a flex inset 
 \emph on
 must 
@@ -18295,6 +18295,7 @@ getSizeCSS()
 status collapsed
 
 \begin_layout Plain Layout
+
 src/FontInfo.cpp
 \end_layout