sender, if known, shall be notified of the fact of nondelivery, and be given an opportunity to prepay the return postage. aSCDcH SECTION  1187 . Special Delivery . — Mailable matter upon which a special-delivery stamp shall be duly affixed in addition to the lawful postage thereon shall be entitled to immediate delivery within two kilometers of the post office to which addressed or wit hin such greater limits as may be fixed by the Director. When in addition to the stamps required to transmit any letter or package of mail matter through the mails, there shall be attached to the envelope or wrapper ordinary stamps of any denomination to the value of twenty centavos, with the words "special deli very" or their equivalent written or printed on the envelope or wrapper, under such regulations as the Director of Posts may prescribe, the said package shall be handled, transmitted, and delivered in all respects as though it bore a regulation special-del ivery stamp. aTIAES SECTION  1188 . Insufficient Postage on Special-Delivery Letters . — The omission by the sender to place the ordinary postage required upon a letter bearing such special-delivery stamp and otherwise entitled to immediate delivery shall not hinder or delay the  transmission and delivery thereof, but such postage shall be collected upon its delivery, in the manner provided for the collection of deficient postage resulting from the overweight of letters. ARTICLE  III Registration of Mail Matter SECTION  1189 . Establishment of Registry System . — For the greater security of valuable mail matter the Director of Posts shall establish a uniform system of registration, under regulations approved by the Department head. As a part of such system of regist ration he may, in his discretion, provide rules under which the senders or owners of registered matter may be indemnified for losses thereof in the mails, the indemnity to be paid out of postal revenues, but in no case to exceed one hundred pesos for any r egistered piece, or the actual value thereof when that is less than one hundred pesos, and for which no other compensation or reimbursement to the loser has been made. DTCAES SECTION  1190 . Manner of Registering Mail Matter and Paying Registry Fees . — Mail matter shall be registered only on the application of the party posting the same, and the fee therefor shall not exceed forty centavos in addition to the regular postage. Lett ers upon the official business of the Bureau of Posts which require registering shall be registered free of charge; but with this exception the Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 355