Save the #default_value of custom fields when editing comments I added a field select list comments in a hook_form_alter. When you select and save the comment, I do not know how to preserve the value of this field when editing this comment.
My Code

function comment_author_form_comment_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if ($form_id == 'comment_node_zayavka_form') {
    $query = db_select('node', 'n')
      -&gt;fields('n', array('type', 'uid', 'title', 'nid'))
      -&gt;condition('n.type', 'brigada_type', '=');
    $result = $query-&gt;execute();
    $brigade_list = array();
    foreach ($result as $value) {
      if ($user-&gt;uid != 1) {
        if ($value-&gt;uid == $user-&gt;uid) {
          $brigade_list[$value-&gt;nid] = $value-&gt;title;
        }
      }
      else {
        $brigade_list[$value-&gt;nid] = $value-&gt;title;
      }
    }
    $form['select_brigade'] = array(
      '#type' =&gt; 'select',
      '#title' =&gt; t('Select brigade'),
      '#options' =&gt; $brigade_list,
      '#description' =&gt; t('Please select the team that was sent to you with reference to this application.'),
      '#required' =&gt; TRUE,
      '#default_value' =&gt; variable_get('comment_field_brigade_selection', 0),
    );
  }
}
I finally solved my problem, has created a field using field_create_field and attached it to the essence of my comment present the type of material
My code for the solutions in the Custom Module:

/**
 * Реализация hook_enable().
 */
function comment_author_enable() {
    foreach (_comment_author_select_field_create() as $field) {
        field_create_field($field);
    }
    foreach (_comment_author_select_field_instances() as $instance) {
        $instance['entity_type'] = 'comment';
        $instance['bundle'] = 'comment_node_zayavka';
        field_create_instance($instance);
    }
}
function _comment_author_select_field_create(){
  $fields['brigade_select'] = array(
    'field_name' =&gt; 'brigade_select',
    'label' =&gt; t('Select an option from the list'),
    'type' =&gt; 'list_text',
    'cardinality' =&gt; '1', // change this to -1 to enable ctrl+select
    'foreign keys' =&gt; array(),
    'indexes' =&gt; array(
      'value' =&gt; array(
        0 =&gt; 'value',
      ),
    ),
    'module' =&gt; 'list',
    'settings' =&gt; array(
      'allowed_values_function' =&gt; '_comment_author_options_list',
    ),
  );

  return $fields;
}
function _comment_author_select_field_instances()  {
    $instances['brigade_select'] = array(
    'field_name' =&gt; 'brigade_select',
    'label' =&gt; t('Select brigade'),
    'description' =&gt; t('Please select the team that was sent to you with reference to this application.'),
    'default_value' =&gt; NULL,    // add a default value here that matches your key =&gt; index values
    'display' =&gt; array(
      'default' =&gt; array(
        'label' =&gt; 'above',
        'module' =&gt; 'list',
        'settings' =&gt; array(),
        'type' =&gt; 'list_default',
        'weight' =&gt; -1,
      ),
      'teaser' =&gt; array(
        'label' =&gt; 'above',
        'settings' =&gt; array(),
        'type' =&gt; 'hidden',
        'weight' =&gt; -1,
      ),
    ),
    'required' =&gt; 1,
    'settings' =&gt; array(
      'user_register_form' =&gt; FALSE,
    ),
    'widget' =&gt; array(
      'active' =&gt; 1,
      'module' =&gt; 'options',
      'settings' =&gt; array(),
      'type' =&gt; 'options_select',
      'weight' =&gt; '-1',
    ),
  );
  return $instances;
}
function _comment_author_options_list(){
global $user;
$query = db_select('node', 'n')
    -&gt;fields('n', array('type', 'uid', 'title', 'nid'))
    -&gt;condition('n.type', 'brigada_type', '=');
 $result = $query-&gt;execute();
 $brigade_list = array();
    foreach($result as $value){
        if($user-&gt;uid != 1){
            if($value-&gt;uid == $user-&gt;uid){
             $brigade_list[$value-&gt;nid] = $value-&gt;title;
            }   
        }else{
        $brigade_list[$value-&gt;nid] = $value-&gt;title;
        }
    }
    return $brigade_list;
}