Any person desiring notice of any order or filing pertaining to a decedent‘s estate in which he has a financial or property interest may file a demand for notice with the court at any time after the death of the decedent stating the name of the decedent, the nature of his interest in the estate and the demandant’s address or that of his attorney. The demandant shall mail a copy of the demand to the personal representative if one has been appointed. After filing of a demand, no order or filing to which the demand relates shall be made or accepted without notice as prescribed in section 14-1401 to the demandant or his attorney. The validity of an order which is issued or filing which is accepted without compliance with this requirement shall not be affected by the error, but the petitioner receiving the order or the person making the filing may be liable for any damage caused by the absence of notice. The requirement of notice arising from a demand under this provision may be waived in writing by the demandant and shall cease upon the termination of his interest in the estate.