Consistency: "Unix" ==> "\UNIX{}"
diff --git a/Doc/libwww.tex b/Doc/libwww.tex
index f341ea7..8cfc09d 100644
--- a/Doc/libwww.tex
+++ b/Doc/libwww.tex
@@ -8,8 +8,8 @@
World-Wide Web (WWW) clients and/or services, and a few modules
related to news and email. They are all implemented in Python. Some
of these modules require the presence of the system-dependent module
-\code{sockets}, which is currently only fully supported on Unix and
-Windows NT. Here is an overview:
+\code{sockets}\refbimodindex{socket}, which is currently only fully
+supported on \UNIX{} and Windows NT. Here is an overview:
\begin{description}