Apparently it read as "times" in screen readers.
form
.addClass('dialogbox')
- .append('<button class="close">×</button>')
+ .append('<button class="close" title="' + SN.msg('popup_close_button') + '">×</button>')
.closest('.notice-options')
.addClass('opaque');
// TRANS: Localized tooltip for '...' expansion button on overlong remote messages.
$messages['showmore_tooltip'] = _m('TOOLTIP', 'Show more');
+ $messages['popup_close_button'] = _m('TOOLTIP', 'Close popup');
$messages = array_merge($messages, $this->getScriptMessages());