The IP Code of the Philippines does not expressly state that patented products must bear patent markings which serve to notify the public and competitors that products are patented. However, Section 80 of the IP Code provides that “damages cannot be recovered for acts of infringement committed before the infringer knew, or had reasonable grounds to know of the patent.

It is presumed that the infringer knew of the patent if on the patented product, or on the container or package in which the article is supplied to the public, or on the advertising material relating to the patented product or process, are placed the words Philippine Patent with the number of the patent.” This simply means that notice of infringement may be served either actually, or constructively by said patent marking. 

The provision specifies where the patent marking can be made. Best practice is to mark the product itself, but markings on the container or packaging of the product, and even advertising materials related to the patent are likewise acceptable. There is also no indication as to what type of patent can be marked. The provision therefore applies to all types of patents, since the law allows markings or notices to be made on advertisements.  

It is in the interests of the patentee to be aware of the notice requirement in order to recover damages from infringement. Moreover, no damages can be recovered from acts of infringement committed more than four years before the filing of the action.  

There are no known cases dealing with patent markings alone, but an interesting case is that of Vasquez Building Systems Corporation and Edgardo Vasquez v Avida Land Corporation. Vasquez, the inventor, filed a patent application for his invention referring to a process of using column panels and roofing assembly to build a home. While his patent was pending, he notified the public by placing his notice of patent pending on top of the roof of his housing exhibit. His patent was granted in 1994. Through his corporation, Vasquez obtained several construction contracts from Avida using his patented invention. 

However, some time in 1997, Vasquez found out that Avida was using his invention in other mass housing projects awarded to another contractor. Vasquez sent several letters to Avida notifying it that respect must be given to his patented invention, but was ignored. Vasquez sued Avida for patent infringement. The evidence of infringement presented by Vasquez was found to be sufficient and damages of PHP 96.5 million, which at current exchange rate is about US$1.9 million, were awarded.