I want to hide some profile (previously profile2) fields from registration page. That should be easy, just hook_form_alter and:
$form['profile_additional']['field_sth_sth']['#access'] = FALSE;
But for the life of me I can't find whole ['profile_additional'] element, only standard registration form elements. How to access profile form on registration page from this hook?
(BTW setting this field as invisible works only for "customized for: account" part, not for registration page).