* lisp/emacs-lisp/package.el (package-pinned-packages): Doc fix.

* etc/NEWS: Related edit.

etc/NEWS

@@ -816,8 +816,8 @@ Use `electric-indent-mode' instead.
 
 ** Package
 
-FIXME
-*** New option `package-pinned-packages'.
+*** New option `package-pinned-packages'.  This is useful if you have multiple
+archives enabled, with more than one offering a package that you want.
 
 FIXME
 *** New options `package-check-signature' and `package-unsigned-archives'.

lisp/ChangeLog

+2014-06-03  Glenn Morris  <rgm@gnu.org>
+
+	* emacs-lisp/package.el (package-pinned-packages): Doc fix.
+
 2014-06-02  Eli Zaretskii  <eliz@gnu.org>
 
 	* menu-bar.el (menu-bar-open): Fix invocation via M-x.

lisp/emacs-lisp/package.el

@@ -229,18 +229,25 @@ a package can run arbitrary code."
   :version "24.1")
 
 (defcustom package-pinned-packages nil
-  "An alist of packages that are pinned to a specific archive
-
-Each element has the form (SYM . ID).
- SYM is a package, as a symbol.
- ID is an archive name. This should correspond to an
- entry in `package-archives'.
-
-If the archive of name ID does not contain the package SYM, no
-other location will be considered, which will make the
-package unavailable."
+  "An alist of packages that are pinned to specific archives.
+This can be useful if you have multiple package archives enabled,
+and want to control which archive a given package gets installed from.
+
+Each element of the alist has the form (PACKAGE . ARCHIVE), where:
+ PACKAGE is a symbol representing a package
+ ARCHIVE is a string representing an archive (it should be the car of
+an element in `package-archives', e.g. \"gnu\").
+
+Adding an entry to this variable means that only ARCHIVE will be
+considered as a source for PACKAGE.  If other archives provide PACKAGE,
+they are ignored (for this package).  If ARCHIVE does not contain PACKAGE,
+the package will be unavailable."
   :type '(alist :key-type (symbol :tag "Package")
                 :value-type (string :tag "Archive name"))
+  ;; I don't really see why this is risky...
+  ;; I suppose it could prevent you receiving updates for a package,
+  ;; via an entry (PACKAGE . NON-EXISTING).  Which could be an issue
+  ;; if PACKAGE has a known vulnerability that is fixed in newer versions.
   :risky t
   :group 'package
   :version "24.4")