#4697: clarify that the functions are Unix-only.
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 588b3e1..57b83d3 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -197,6 +197,8 @@
       >>> subprocess.getstatusoutput('/bin/junk')
       (256, 'sh: /bin/junk: not found')
 
+   Availability: UNIX.
+
 
 .. function:: getoutput(cmd)
    Return output (stdout and stderr) of executing *cmd* in a shell.
@@ -208,6 +210,8 @@
       >>> subprocess.getoutput('ls /bin/ls')
       '/bin/ls'
 
+   Availability: UNIX.
+
 
 Exceptions
 ^^^^^^^^^^