diff --git a/Doc/lib/libsocket.tex b/Doc/lib/libsocket.tex
index 1f5bcaa..51c4a2f 100644
--- a/Doc/lib/libsocket.tex
+++ b/Doc/lib/libsocket.tex
@@ -7,7 +7,8 @@
 
 This module provides access to the BSD \emph{socket} interface.
 It is available on all modern \UNIX{} systems, Windows, MacOS, BeOS,
-OS/2, and probably additional platforms.
+OS/2, and probably additional platforms.  \note{Some behavior may be
+platform dependent, since calls are made to the operating system socket APIs.}
 
 For an introduction to socket programming (in C), see the following
 papers: \citetitle{An Introductory 4.3BSD Interprocess Communication