http://drupal.org/node/114774#book_module

encouraged to replace that with $severity WATCHDOG_DEBUG for consistency.

drupal_set_breadcrumb() should be used instead.

used instead.

cache_clear_all() should be used instead.

D6.

'administer permissions' and the path 'admin/user/access' has changed to
'admin/user/permissions'.

hook_enable/disable functions in node access modules in D6

matched by the rule itself.