Added \platform annotations.
diff --git a/Doc/lib/libmsvcrt.tex b/Doc/lib/libmsvcrt.tex
index 481117b..7e4c417 100644
--- a/Doc/lib/libmsvcrt.tex
+++ b/Doc/lib/libmsvcrt.tex
@@ -2,6 +2,7 @@
          Useful routines from the MS VC++ runtime}
 
 \declaremodule{builtin}{msvcrt}
+  \platform{Windows}
 \modulesynopsis{Miscellaneous useful routines from the MS VC++ runtime.}
 \sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}