--- a/Doc/lib/libsubprocess.tex
+++ b/Doc/lib/libsubprocess.tex
@@ -11,6 +11,9 @@
 connect to their input/output/error pipes, and obtain their return
 codes.  This module intends to replace several other, older modules
 and functions, such as:
+
+% XXX Should add pointers to this module to at least the popen2
+% and commands sections.
 
 \begin{verbatim}
 os.system