I was thinking of that line in the case of:  Within the model's associated controller, attempting a static call ( MyModel::A_CONST ) before a normal class call ( $this->MyModel->anything(); ) results in a failure.  App::uses() makes the model immediately available in the controller without a normal class call.  Perhaps there's a more encompassing statement to highlight the importance of having App::uses('AppModel', 'Model') in your models.  I'm all ears.