diff -r 014060738f7f PCbuild/readme.txt
--- a/PCbuild/readme.txt	Sun Aug 24 09:10:58 2014 +0300
+++ b/PCbuild/readme.txt	Sat Aug 30 22:15:14 2014 +1200
@@ -88,6 +88,14 @@
    -r                  Rebuild instead of just building
    -e                  Use get_externals.bat to fetch external sources
 
+Note that normal MSBuild switches can also be passed. These should be
+passed after specifying any of the above switches. An example of this:
+
+build.bat -e -d /m
+
+If the symbol '=' is used, then it should be wrapped in quotes.
+
+build.bat -e -d "/p:externalsDir=P:\cpython-externals"
 
 Legacy support
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