What's meaning of '#programmed' attribute of a form array in drupal?

What's meaning 开发者_开发百科of '#programmed' attribute of a form array in drupal? I didn't find any documentation for it in drupal.org

Drupal allows you to submit forms from a programmatically, which can be really useful for making comments/nodes etc from a custom module. '#programmed' is set to true when a form is submitted by a function using drupal_execute. see more here: http://api.drupal.org/api/function/drupal_execute/6