EDIT

  // ---- footnotes --- //

  $form['footnotes'] = array(

    '#type' => 'fieldset',

    '#title' => t('Footnotes'),

    '#collapsible' => FALSE,

    '#collapsed' => FALSE,

    '#description' => t('Taxa data such authors, synonyms names, descriptions,

      media or distribution areas may have annotations or footnotes. When the

      footnotes are enabled they will be visible (if they exist).'),

  );

  $form['footnotes']['cdm_dataportal_all_footnotes'] = array(

    '#type' => 'checkbox',

    '#title' => t('Do not show footnotes'),

    '#default_value' => variable_get('cdm_dataportal_all_footnotes', CDM_DATAPORTAL_ALL_FOOTNOTES),

    '#description' => t('Check this if you do not want to show any footnotes'),

  );

  $form['footnotes']['cdm_dataportal_annotations_footnotes'] = array(

    '#type' => 'checkbox',

    '#title' => t('Do not show annotation footnotes'),

    '#default_value' => variable_get('cdm_dataportal_annotations_footnotes', CDM_DATAPORTAL_ANNOTATIONS_FOOTNOTES),

    '#description' => t('Check this if you do not want to show annotation footnotes'),

  );