SECTION  2457 . Action when Owner Makes no Return, or is Unknown or in Doubt, or Land and Improvements Separately Owned.  — If the owner of any parcel of real estate shall fail to make a return thereof, or if the city assessor and collector is unable to disco ver the owner of any real estate, he shall nevertheless list the same for taxation, and charge the tax against the true owner, if known, and if unknown then as against an unknown owner. In case of doubt or dispute as to ownership of real estate, the taxes  shall be levied against the possessor or possessors thereof. Where it shall appear that there are separate owners of the land and the improvements thereon, a separate assessment of the property of each shall be made. [183-49.] SECTION  2458 . Action in Case Real Estate has Escaped Taxation . — If it shall come to the knowledge of the city assessor and collector that any taxable real estate in the city has escaped listing, it shall be his duty to list and value the same at the time  and in the manner provided in the next succeeding section and to charge against the owner thereof the taxes due for the current year and for all other years since the original assessment under the city charter was made, and the taxes thus assessed shall be  legal and collectible by all the remedies herein provided, and if the failure of the city assessor and collector to assess such taxes at the time when they should have been assessed was due to any fault or negligence on the part of the owner of such prope rty, then penalties shall be added to such back taxes as though they had been assessed at the time when they should have been assessed. [183-50; 2257-3.] SECTION  2459 . When Assessment may be Increased or Reduced.  — The city assessor and collector shall, during the first fifteen days of December of each year, add to his list of taxable real estate in the city the value of the improvements placed upon such pr operty during the preceding year, and any property which is taxable and which has theretofore escaped taxation. He may during the same period revise and correct the assessed value of any or all parcels of real estate in the city which are not assessed at t heir true money value, by reducing or increasing the existing assessments as the case may be. He shall give notice by publication for ten days prior to December first in two newspapers of general circulation published in the city, one printed in English an d one in Spanish, that he will be present in his office for that purpose on said days, and he shall further notify in writing each person the amount of whose tax will be changed by such action or such proposed change, by delivering or mailing such notifica tion to such person or his authorized agent at the last known address of such owner or agent in the Philippine Islands Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 738