What is "Patent Marking?"

Patent marking is a way for a patent owner to let the public know an article is believed to be covered by one or more of its patents.  This is referred to as “constructive notice” to the public that the article may embody patent rights.

What Purpose Does Patent Marking Serve?

Some people mark their products with applicable patent numbers to discourage copying: “Hmm – this company went to the trouble of obtaining patents.  They may also be willing to enforce those patents.”  

Others use it as a marketing tool:  “Look!  The latest in patented technology!”

But the main legal advantage provided by proper patent marking has to do with the amount of damages a patent owner can seek in an infringement suit.  If an infringer was given constructive notice of patents through a properly marked article, all sales of its infringing articles may be used in calculating money damages.  If the patented article wasn’t marked, the patent owner may only seek damages dated from when the infringer was given actual notice of the patents.  

What Does Patent Marking Look Like?

Marking includes the word “patent” or the abbreviation “pat.” followed by the relevant patent numbers.  (Some precede this with “U.S.” since different countries have different requirements).  This notice can be printed or stamped directly on an article, or printed on a label attached to the article.  If the article is too small, the notice can be printed on packaging for the article or on documentation that ships with it.

What If Lots of Patent Numbers Apply?

Patent owners now have the option of providing a URL which links to a list of patent numbers associated with a given article.  Such a notice might look like: “Patent www.CompanyABC.com/patents”.  This virtual marking makes it much easier to provide current, up-to-date patent information to the public.

When Can a Product Be Marked or Described as “Patent Pending?”

As long as a relevant provisional, utility, design, or plant patent application has been filed and remains pending, the article may be marked or described as “patent pending.”

How Big a Problem Is an Out-of-Date Listing of Expired Patents on an Article?

As long as the expired patents used to cover some aspect of the article on which they are listed, it’s okay if they remain.  A periodic review of all patent markings is not only a good way to facilitate the removal of expired patent numbers, but also to enable the addition of newly issued patents.