hook_form(&$node, &$param) &$node The node being added or edited. &$param The hook can set this variable to an associative array of attributes to add to the enclosing \<form\> tag. Return value A string containing HTML defining form elements to be displayed in the node edit form. This is called from: // Get the node-specific bits. // We can't use node_invoke() because $param must be passed by reference. $function = node_get_module_name($edit) .'_form'; $param = array(); if (function_exists($function)) { $form .= $function($edit, $param); } My question is: why $node is a reference form hook_form? To edit the node we have hook_load and hook_validate. I propose changing the documentation. Still a module author can write &$node and edit $node in his _form but at least do not document it so. Regards NK