Drupal Association members fund grants that make connections all over the world.
The $rdf_namespaces variable is not found in the default maintenance-page.tpl, but Zen has it and it causes PHP notices when the maintenance page is viewed:
Notice: Undefined variable: rdf_namespaces in include() (line 17 of sites/all/themes/zen/templates/maintenance-page.tpl.php).
This variable needs to be removed.
First reported here: http://drupal.org/node/1179128#comment-5221910