'undo-failure' => 'The edit could not be undone due to conflicting intermediate edits.',
'undo-norev' => 'The edit could not be undone because it does not exist or was deleted.',
'undo-summary' => 'Undo revision $1 by [[Special:Contributions/$2|$2]] ([[User talk:$2|talk]])',
+'undo-summary-username-hidden' => 'Undo revision $1 by a hidden user',
# Account creation failure
'cantcreateaccounttitle' => 'Cannot create account',