Forum & Topic Icon "Not permissions"

I wanted to ask if it will be possible to integrate a icon "not permission" such as "password forums" that icon must be "fa-eye-slash".

i have made with a >hook that check view permission easy:

<if test="!$this->registry->getClass('class_forums')->forumsCheckAccess( $forum_data['id'], 0, 'forum', $forum_data, true )">
<i class="fa fa-eye-slash" data-tooltip="{$forum_data['permission_custom_error']}"></i>
<else />
<i class="fa fa-comments"></i>
</if>

this is for forums... but that is possible already also with topic. ($forum_data['permission_custom_error'] = "custom message setted on forum configs")