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Make sure the KEYS file in subversion is up-to-date with the latest, exported public keys of the committers (and most importantly, the release manager). For more information on this file, see this page.
For *nix systems use the following command to add a missing key to the KEYS file:
(gpg --list-sigs AB76196 && gpg -a --export AB76196) >> KEYS
Tag the release
Tag the trunk based on the version of the release (e.g. svn copy to tags/release-3.3)
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