+% For references that don't fit into this pattern, there's a more complex
+% definition syntax using |\defxref*|:
+% \begin{grammar}
+% <definition> ::= \[[
+% "\\defxref*"
+% "{" <prefix> "}"
+% "{" <expansion> "}"
+% \]]
+% \end{grammar}
+% The \<expansion> is given four arguments.
+% \begin{itemize}
+% \item |#1| is the name of a macro which should be given two arguments,
+% respectively the reference name and the body of the hyperlink to
+% generate.
+% \item |#2| is the name of a macro to apply to the reference name to typeset
+% the actual reference.
+% \item |#3| is the \<mangle> token, or |\relax|.
+% \item |#4| is the reference name itself.
+% \end{itemize}
+%