Bug #1501122: mention __gt__ &co in description of comparison order.
diff --git a/Doc/ref/ref5.tex b/Doc/ref/ref5.tex
index 89f9977..909e5bb 100644
--- a/Doc/ref/ref5.tex
+++ b/Doc/ref/ref5.tex
@@ -907,7 +907,10 @@
the values of two objects. The objects need not have the same type.
If both are numbers, they are converted to a common type. Otherwise,
objects of different types \emph{always} compare unequal, and are
-ordered consistently but arbitrarily.
+ordered consistently but arbitrarily. You can control comparison
+behavior of objects of non-builtin types by defining a \code{__cmp__}
+method or rich comparison methods like \code{__gt__}, described in
+section~\ref{specialnames}.
(This unusual definition of comparison was used to simplify the
definition of operations like sorting and the \keyword{in} and
@@ -952,7 +955,8 @@
a dictionary for emptiness by comparing it to \code{\{\}}.}
\item
-Most other types compare unequal unless they are the same object;
+Most other objects of builtin types compare unequal unless they are
+the same object;
the choice whether one object is considered smaller or larger than
another one is made arbitrarily but consistently within one
execution of a program.