The utility classes option provides a collection of CSS classes. The option is available on all elements in Glazed Builder including containers. By default the suggested classes are a selection of Bootstrap helper classes and a selection of Glazed helper classes. You can also click the link "Switch to custom text input" and put in additional css classes, without restriction.

If you are looking to control which classes are shown in the suggestions list, Glazed Builder provides 2 ways to do this.

1. Define classes in a theme

Glazed Builder will scan your theme's info file to build the list of utility classes. You can enter one new class per line using the following format:

glazed_classes[your-class]   = Class Label

Make sure to clear all Drupal caches after updating your theme's info file. Your custom classes will be added to your theme's option group.

2. Define classes in a module

Glazed Builder provides a hook hook_glazed_builder_classes_alter that allows you to modify the $glazed_classes array. In the following example code replace mymodule with your module's name and put the code in your .module file:

/**
 * Implements hook_glazed_builder_classes_alter().
 */
function mymodule_glazed_builder_classes_alter(&$glazed_classes) {
  $glazed_classes['optgroup-my-group'] = t('My Option Group');
  $glazed_classes['my-class'] = t('My label');
}

After adding the function you'll have to clear caches for the hook to be picked up.