How to programmatically create forums and containers (not forum topics)? I need to create containers and forums using rules.

If I use the action "Create new entity" -> "Taxonomy term" I got that by default the new term created is treated as a forum, not a container. How can I either convert it to be a container or, using a custom PHP script, create directly a container ?

I tought it was some variable of the term to make the difference, but if I use Devel over both containers or forums they looks the same.

I found http://www.unibia.com/unibianet/drupal/how-create-drupal-forums-and-containers-programmatically but it refers to D6, and in D7 I don't know what to pass as $form and $form_state to the forum_form_container() function.
I think I got it.. not in some fields, not (directly) in some DB table.. the difference between forum and containers is in the variables:

$containers = variable_get('forum_containers', array());
$containers[] = 14;
variable_set('forum_containers', $containers);