Drupal Menu

The minimum requirements in implementing Drupal hook_menu is
1. title
2. page callback. If there's no default menu tabs or menu default has no page callback, this is used one
3. access callback

Then if for the tab menu is this one
0. there is at leat two tab menus
1. type: MENU_DEFAULT_LOCAL_TASK or MENU_LOCAL_TASK
2. title
3. page callback
4. access callback
5. weight

Drupal Menu