* emacs/package.texi (Package Installation): Mention package-pinned-packages.

* etc/NEWS: Related markup.

doc/emacs/ChangeLog

+2014-06-03  Glenn Morris  <rgm@gnu.org>
+
+	* package.texi (Package Installation): Mention package-pinned-packages.
+
 2014-06-02  Glenn Morris  <rgm@gnu.org>
 
 	* misc.texi [iftex]: Update chapter summary.

doc/emacs/package.texi

@@ -167,6 +167,13 @@ directory name of the package archive.  You can alter this list if you
 wish to use third party package archives---but do so at your own risk,
 and use only third parties that you think you can trust!
 
+@vindex package-pinned-packages
+  If you have more than one package archive enabled, and some of them
+offer different versions of the same package, you may find the option
+@code{package-pinned-packages} useful.  You can add package/archive
+pairs to this list, to ensure that the specified package is only ever
+downloaded from the specified archive.
+
   Once a package is downloaded and installed, it is @dfn{loaded} into
 the current Emacs session.  Loading a package is not quite the same as
 loading a Lisp library (@pxref{Lisp Libraries}); its effect varies

etc/NEWS

@@ -816,6 +816,7 @@ Use `electric-indent-mode' instead.
 
 ** Package
 
++++
 *** New option `package-pinned-packages'.  This is useful if you have multiple
 archives enabled, with more than one offering a package that you want.