Validations as warning for model attributes using backbone.validations plugin

Question

As the subject suggests, i am using backbone validation plugin for form fields validation. It works fine for fields to be validated and stop form submission with errors.

I would like to implement a validation which acts like warning. User will see the validation message but should be able to submit the form.

validation: {
    password: {
        required: true,
        // Custom Validation Rule
        warning: {
            pattern: /regexPattern/,
            msg: "Medium Strength Password"
        }
    }
}

Plugin documentation - http://thedersen.com/projects/backbone-validation/

I didn't find any helpful reference to implement the ask or probably i might have missed that so any pointers will be helpful for me.