[http://hg.mozilla.org/build/braindump/file/dc0e5c578109/releases-related Script available here (beta2release.sh)]
<pre>
# Adjust VERSION variable which stands for the current Firefox version in mozilla-release
RELEASE_TAG="FIREFOX_RELEASE_$VERSION"
hg -R mozilla-beta tag -r $beta_rev -u "$HG_USER" -m "Added tag $RELEASE_BASE_TAG for changeset $beta_rev. CLOSED TREE a=releaseDONTBUILD" $RELEASE_BASE_TAG