Before a person is accepted for voluntary inpatient treatment, an explanation shall be made to him of such treatment, including the types of treatment in which he may be involved, and any restraints or restrictions to which he may be subject, together with a statement of his rights under this act. Consent shall be given in writing upon a form adopted by the department. The consent shall include the following representations: That the person understands his treatment will involve inpatient status; that he is willing to be admitted to a designated facility for the purpose of such examination and treatment; and that he consents to such admission voluntarily, without coercion or duress; and, if applicable, that he has voluntarily agreed to remain in treatment for a specified period of no longer than 72 hours after having given written notice of his intent to withdraw from treatment. The consent shall be part of the person's record.