Section 15 - Assignments of contracts and orders to be filed1. No assignment of one or more contracts for the performance of labor or the furnishing of materials for the improvement of real property or of the money or any part thereof due or to become due therefor, nor an order drawn by a contractor upon the owner of such real property for the payment of such money, nor an order drawn by a subcontractor upon a contractor or subcontractor for such payment, nor an order drawn by an owner upon the maker of a building loan, nor an assignment of moneys due or to grow due under a building loan contract, shall operate to reduce the lien of a subcontractor, laborer or materialman, except as provided in sections thirteen and twenty-six of this chapter; nor shall any such assignment or order be valid for any purpose, unless a "Notice of Assignment" meeting the requirements of subdivision two of this section or the contract (other than a building loan contract) or a statement containing the substance thereof and such assignment or a copy of each or a copy of such order, be filed within ten days after the date of such assignment or such order, in the office of the county clerk of each county wherein real property improved or to be improved to which the assignment or order relates is situated and such assignment or order shall have effect and be enforceable from the time of such filing, and no such assignment or order shall have any validity until the same shall have been so filed, and every such assignment or order, not filed shall be absolutely void as against a subsequent assignee in good faith and for valuable consideration, whose assignment or order is first duly filed. Such clerk shall enter the facts relating to such assignment or order in the "lien docket" or in another book provided by him for such purpose. Each such assignment shall be indexed by the name of the assignor and each such order shall be indexed by the name of the drawer.2. A "Notice of Assignment" filed pursuant to subdivision one of this section shall be used only in the case of money advanced or to be advanced to a contractor or subcontractor upon the assignment of one or more contracts for the performance of labor or the furnishing of materials for the improvement of real property, or of the money or any part thereof due or to become due therefor. The said notice shall contain (a) the names and addresses of the assignor and assignee, (b) the date of the assignment, and the date the assignment will terminate, which termination date shall not be more than two years after the date of the assignment, (c) the maximum balance of advances outstanding to be secured by the assignment, (d) a statement of each county wherein the real property involved in the contracts is or may be situated, and (e) either a specific description of the substance of the contract or contracts assigned, including an identification of the real property involved in each such contract, or a statement that the assignment covers all or a specified class of the assignor's accounts or contract rights. If the contract or contracts assigned are described specifically the real property identification shall be sufficient if it includes the name of the record owner and the location of the real estate by street and number and town or city or, if the real estate is in the city of New York, by county, except that if the real estate is in the city of New York or counties of Nassau or Onondaga, where the block system of recording or registering and indexing conveyances is in use, the notice must also specify the block in which the real estate is situated.3. A "Notice of Assignment" may be continued in effect beyond the stated termination date by filing within sixty days prior to the termination date a subsequent "Notice of Assignment" entitled "Second Notice of Assignment" or "Third Notice of Assignment", which identifies the prior "Notice of Assignment" to which it relates and otherwise conforms to the requirements of subdivision two of this section.4. The term "Notice of Assignment" as used in this section includes any amendments but if any amendment extends the assignment to cover additional contracts it is effective as to the added contracts only from the date of the filing.