Any options for the jQuery UI Tag-it widget. See the documentation for all available options.
Adding a tags editor in a CRUD form configuration:
<?php
return array(
'label' => '',
'renderer' => 'Nos\Renderer_Tag',
'renderer_options' => array(
'model' => 'Model_Tag',
'label_column' => 'tag_label',
'relation_name' => 'tags'
),
);