A policy may contain additional provisions not inconsistent with this Code and which are:
1. Required to be inserted by the laws of the insurer's domicile;
2. Necessary, on account of the manner in which the insurer is constituted or operated, in order to state the rights and obligations of the parties to the contract; or
3. Desired by the insurer and neither prohibited by law nor in conflict with any provisions required to be included therein.
Laws 1957, p. 367, § 3614.