Hello, I am having a look at the documentation for hook_link(): It seems to me that there was a mistake: http://api.drupal.org/api/function/hook_link/5 http://api.drupal.org/api/function/hook_link When $type == 'comment' the second argument returns the comment object and not NULL (see hook_link() in quote.module, for example). I have updated the documentation for D6 accordingly (but not yet for D5). It will be visible at api.d.o in a few hours, I guess. I hope I have not introduced a bigger mistake. Blessings, Augustin.