Elaborate the explanation of different flavors of _* identifiers.
Fixes SF bug #520325.
diff --git a/Doc/ref/ref2.tex b/Doc/ref/ref2.tex
index e0f1e49..76c5cc5 100644
--- a/Doc/ref/ref2.tex
+++ b/Doc/ref/ref2.tex
@@ -320,25 +320,39 @@
\subsection{Reserved classes of identifiers\label{id-classes}}
Certain classes of identifiers (besides keywords) have special
-meanings. These are:
-
-\begin{tableiii}{l|l|l}{code}{Form}{Meaning}{Notes}
-\lineiii{_*}{Not imported by \samp{from \var{module} import *}}{(1)}
-\lineiii{__*__}{System-defined name}{}
-\lineiii{__*}{Class-private name mangling}{}
-\end{tableiii}
-
-See sections: \ref{import}, ``The \keyword{import} statement'';
-\ref{specialnames}, ``Special method names'';
-\ref{atom-identifiers}, ``Identifiers (Names)''.
-
-Note:
+meanings. These classes are identified by the patterns of leading and
+trailing underscore characters:
\begin{description}
-\item[(1)] The special identifier \samp{_} is used in the interactive
-interpreter to store the result of the last evaluation; it is stored
-in the \module{__builtin__} module. When not in interactive mode,
-\samp{_} has no special meaning and is not defined.
+
+\item[\code{_*}]
+ Not imported by \samp{from \var{module} import *}. The special
+ identifier \samp{_} is used in the interactive interpreter to store
+ the result of the last evaluation; it is stored in the
+ \module{__builtin__} module. When not in interactive mode, \samp{_}
+ has no special meaning and is not defined.
+ See section~\ref{import}, ``The \keyword{import} statement.''
+
+ \note{The name \samp{_} is often used in conjunction with
+ internationalization; refer to the documentation for the
+ \ulink{\module{gettext} module}{../lib/module-gettext.html} for more
+ information on this convention.}
+
+\item[\code{__*__}]
+ System-defined names. These names are defined by the interpreter
+ and it's implementation (including the standard library);
+ applications should not expect to define additional names using this
+ convention. The set of names of this class defined by Python may be
+ extended in future versions.
+ See section~\ref{specialnames}, ``Special method names.''
+
+\item[\code{__*}]
+ Class-private names. Names in this category, when used within the
+ context of a class definition, are re-written to use a mangled for
+ to help avoid name clashes between ``private'' attributes of base
+ and derived classes.
+ See section~\ref{atom-identifiers}, ``Identifiers (Names).''
+
\end{description}