[saegeek]

Hi,
There is also another case where a blacklist could be useful.
When there are thousands of model attributes a blacklist is more quick than a whitelist :
This could be very time saving.

one dirty example:

if ($model->validate('*',array('except'=>'title'))) 

My another suggestion for a blacklist was @ model rules:

public function rules() {
return array(
    array('title','required','skip'=>'at_a_specified_scenario'),
);

[samdark]

It can lead to significant security issues. Will not be in Yii core.