Extension:WikiEditor

jQuery(document).ready(function ($) {

       $('#wpTextbox1').wikiEditor('addToToolbar', {
               section: 'advanced',
               group: 'format',
               tools: {
                       buttonId: {
                               label: 'Comment visible only for editors',
                               type: 'button',
                               icon: '//upload.wikimedia.org/wikipedia/commons/f/f9/Toolbaricon_regular_S_stroke.png',
                               action: {
                                       type: 'encapsulate',
                                       options: {
                                               pre: ""
                                       }
                               }
                       }
               }
       });

});