Section 10 - Filing of notice of lien1. Notice of lien may be filed at any time during the progress of the work and the furnishing of the materials, or, within eight months after the completion of the contract, or the final performance of the work, or the final furnishing of the materials, dating from the last item of work performed or materials furnished; provided, however, that where the improvement is related to real property improved or to be improved with a single family dwelling, the notice of lien may be filed at any time during the progress of the work and the furnishing of the materials, or, within four months after the completion of the contract, or the final performance of the work, or the final furnishing of the materials, dating from the last item of work performed or materials furnished; and provided further where the notice of lien is for retainage, the notice of lien may be filed within ninety days after the date the retainage was due to be released; except that in the case of a lien by a real estate broker, the notice of lien may be filed only after the performance of the brokerage services and execution of lease by both lessor and lessee and only if a copy of the alleged written agreement of employment or compensation is annexed to the notice of lien, provided that where the payment pursuant to the written agreement of employment or compensation is to be made in installments, then a notice of lien may be filed within eight months after the final payment is due, but in no event later than a date five years after the first payment was made. For purposes of this section, the term "single family dwelling" shall not include a dwelling unit which is a part of a subdivision that has been filed with a municipality in which the subdivision is located when at the time the lien is filed, such property in the subdivision is owned by the developer for purposes other than his personal residence. For purposes of this section, "developer" shall mean and include any private individual, partnership, trust or corporation which improves two or more parcels of real property with single family dwellings pursuant to a common scheme or plan. The notice of lien must be filed in the clerk's office of the county where the property is situated. If such property is situated in two or more counties, the notice of lien shall be filed in the office of the clerk of each of such counties. The county clerk of each county shall provide and keep a book to be called the "lien docket," which shall be suitably ruled in columns headed "owners," "lienors," "lienor's attorney," "property," "amount," "time of filing," "proceedings had," in each of which he shall enter the particulars of the notice, properly belonging therein. The date, hour and minute of the filing of each notice of lien shall be entered in the proper column. Except where the county clerk maintains a block index, the names of the owners shall be arranged in such book in alphabetical order. The validity of the lien and the right to file a notice thereof shall not be affected by the death of the owner before notice of the lien is filed.2. Where the county clerk indexes liens in a block index, every notice of lien presented to the clerk of a county of filing, in order to entitle the same to be filed, shall contain in the body thereof, or shall have endorsed thereon, a designation of the number of every block, on the land map of the county, which is affected by the notice of lien. The county clerk shall cause such notice of lien to be entered in the block index suitably ruled to contain the columns listed in the preceding paragraph, under the block number of every block so designated. In cases where a notice of lien shall have been filed without such designation or with an erroneous designation, the county clerk, on presentation of proper proof thereof, shall enter such instrument in the proper index, under the proper block number of every block in which the land affected is situated, and shall, at the same time, make a note of such entry and of the date thereof in every place in which such instrument may have been erroneously indexed, opposite the entry thereof, and also upon the instrument itself, if the same be in his possession or produced to him for the purpose, and the filing of such instrument shall be constructive notice as to property in the block not duly designated at the time of such filing only from the time when the same shall be properly indexed. A county clerk may adopt a new indexing system utilizing electro-mechanical, electronic or any other method he deems suitable for maintaining the indexes.