Implements hook_field_info().
Field settings:
function taxonomy_field_info() {
return array(
'taxonomy_term_reference' => array(
'label' => t('Term reference'),
'description' => t('This field stores a reference to a taxonomy term.'),
'default_widget' => 'options_select',
'default_formatter' => 'taxonomy_term_reference_link',
'settings' => array(
'allowed_values' => array(
array(
'vocabulary' => '',
'parent' => '0',
),
),
),
),
);
}