update to reflect the new significance of the "@" character
diff --git a/Doc/ref/ref2.tex b/Doc/ref/ref2.tex
index 7590592..375604f 100644
--- a/Doc/ref/ref2.tex
+++ b/Doc/ref/ref2.tex
@@ -679,7 +679,7 @@
 \index{delimiters}
 
 \begin{verbatim}
-(       )       [       ]       {       }
+(       )       [       ]       {       }      @
 ,       :       .       `       =       ;
 +=      -=      *=      /=      //=     %=
 &=      |=      ^=      >>=     <<=     **=
@@ -703,5 +703,5 @@
 \index{ASCII@\ASCII}
 
 \begin{verbatim}
-@       $       ?
+$       ?
 \end{verbatim}