The wpforo_notice_show() function shows the notification if, for some reason, the users are not allowed to attach files. For example, if the "Can Attach file" permission is disabled for the guest, registered users, etc.

<script type="text/javascript">
jQuery(document).ready(function($){
var wpforo_wrap = $('#wpforo #wpforo-wrap');
$(wpforo_wrap).on('click', '.attach_cant_view', function(){
wpforo_notice_show(
'<p>&Delta;&epsilon;&nu; έ&chi;&epsilon;&iota;&sigmaf; &tau;&alpha; &alpha;&pi;&alpha;&rho;&alpha;ί&tau;&eta;&tau;&alpha; &delta;&iota;&kappa;&alpha;&iota;ώ&mu;&alpha;&tau;&alpha; !
&Gamma;ί&nu;&epsilon; &mu;έ&lambda;&omicron;&sigmaf;!'
);
});
})
</script>

What does the wpforo_notice_show() function supposed to do?