Document getrefcount().
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index e4cd875..e63e616 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -104,6 +104,12 @@
cannot be trusted).
\end{datadesc}
+\begin{funcdesc}{getrefcount}{object}
+Return the reference count of the \var{object}. The count returned is
+generally one higher than you might expect, because it includes the
+(temporary) reference as an argument to \code{getrefcount()}.
+\end{funcdesc}
+
\begin{datadesc}{last_type}
\dataline{last_value}
\dataline{last_traceback}