A nightly cron job refreshes the GNU ELPA archive from this repository.
-This cron job only creates a new package when the "version" of a package
-is modified. This means that you can safely work on the next version here
-without worrying about the unstable code making it to GNU ELPA, and simply
-update the "version" when you want to release the new code.
+This cron job only creates a new package when the "version" (as specified in
+the foo-pkg.el or in the "Version:" header) of a package is modified.
+This means that you can safely work on the next version here without
+worrying about the unstable code making it to GNU ELPA, and simply update
+the "version" when you want to release the new code.
+
+* Format
+
+Each package should follow the ELPA packaging conventions, but there are
+some differences due to the way the deployment script creates the packages
+and the web-pages from this source code:
+- Multi-file packages can put the package metadata in the main <pkg>.el file
+ in the format used for single-file packages, in which case the script
+ will auto-generate the <pkg>-pkg.el file.
+- the "URL:" header (or :url property) can be used to specify the home page
+ of the package, if it's maintained externally.
+- A "News:" section (or "NEWS" file) can/should be used to list the
+ user-visible changes of each version.
+- The "Package-Type: simple" header can be used to force the creation
+ of a single-file package even when there are several Elisp files in
+ the source (the other files will simply be ignored).
+
+* External branches
+
+Some packages are maintained in external branches. These should be
+appropriately listed in the `externals-list' file.
+There are two different cases: subtrees and externals.
+
+In both cases, a copy of the code is kept in the `elpa' repository and
+should be sync'd with the upstream every once in a while. This copy may
+include local changes, tho ideally these should be kept to a minimum.
+
+In the `subtree' case, the copy of the code is kept here in the
+corresponding `packages/<pkg>' directory. You should be able to "git
+merge -s subtree" from the upstream branch.
+
+In the `external' case, the copy of the code is not kept here but in the
+`externals/<pkg>' branch in the `elpa' repository.
+You can check out all the external packages into the `packages' directory
+with the command:
+
+ make externals