How to add module to admin/config page?
If you do it like this, with the system.module callback for the parent item, you get the nice listing page when you visit 'admin/config/mymodule'

/**
 * Implements hook_menu().
 */
function MYMODULE_menu() {

  $items = [];

  $items['admin/config/mymodule'] = [
    'title'            =&gt; 'My configuration section',
    'description'      =&gt; 'This is the parent item',
    'position'         =&gt; 'left',
    'weight'           =&gt; -100,
    'page callback'    =&gt; 'system_admin_menu_block_page',
    'access arguments' =&gt; ['administer site configuration'],
    'file'             =&gt; 'system.admin.inc',
    'file path'        =&gt; drupal_get_path('module', 'system'),
  ];

  // Need at least one child item before your section will appear.
  $items['admin/config/mymodule/item'] = [
    'title'            =&gt; 'First item',
    'description'      =&gt; 'This is the first child item in the section',
    'page callback'    =&gt; 'mymodule_item_callback',
    'access arguments' =&gt; ['administer site configuration'],
  ];

  return $items;
}