MediaWiki:Common.js

var customizeToolbar = function() {

$( '#wpTextbox1' ).wikiEditor( 'addToToolbar', {
        'sections': {
                'annotations': {
                        'type': 'toolbar', // Can also be 'booklet'
                        'label': 'Annotations'
                        // or 'labelMsg': 'section-emoticons-label' for a localized label
                }
        }
} );
        /* Your code goes here */

};
 
/* Check if we are in edit mode and the required modules are available and then customize the toolbar */
if ( $.inArray( mw.config.get( 'wgAction' ), ['edit', 'submit'] ) !== -1 ) {
        mw.loader.using( 'user.options', function () {
                if ( mw.user.options.get('usebetatoolbar') ) {
                        mw.loader.using( 'ext.wikiEditor.toolbar', function () {
                                $(document).ready( customizeToolbar );
                        } );
                }
        } );
}