Thread:Project:Support desk/Adding new tab like page extra actions

Hello, how can I add a new Tab (Dropdown-List) like the one with the extra action like deletion, protection etc.

What I found out until now:

I need the hook 'SkinTemplateNavigation'.

With the $content_actions['actions']['myaction'] array I can put an entry in the list with deletion etc.

With the $content_actions['views']['myaction'] array I can create a new tab.

But how can I create a list?