minor format

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1140229 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/site/xdoc/guide/substitution.xml b/src/site/xdoc/guide/substitution.xml
index e591250..0a5fffd 100644
--- a/src/site/xdoc/guide/substitution.xml
+++ b/src/site/xdoc/guide/substitution.xml
@@ -38,7 +38,7 @@
 This package provides some useful concrete implementations of the abstract
 Substitutor class. In particular, it provides an implementation that allows
 the application to define "variables" which the input data can reference
-using a syntax such as "${user.name}".
+using a syntax such as <code>${user.name}</code>.
 </p>
 <p>Here's an example of setting up the VariableSubstitutor:</p>
 <source>