This started off as a simple task to change 'Ok' to 'OK' during glossary filter popups for Helen.
In trying to fix this properly, the file lib/Yui/src/notification/js/notification.js which extends ALERT should use M.util.get_String('ok', 'moodle') to provide the strings (among other strings[close,confirm etc).
The issue here is that 'ok' is not a string that is loaded at all in many pages. no one does $PAGE->strings_for_js() and includes 'ok' and 'close' etc... we need to include it at the notification.js level.. somehow.
right now, all notifications buttons are actually not translated.