What Good is "Patent Pending"?

Dear Rich: If I send in a patent application can I then put "patent pending" on my product? Do I have any protections against somebody stealing my idea during my wait to receive my patent. "Patent pending status" is achieved by filing either a regular patent application (RPA) or a provisional patent application (PPA). Placing the "Patent Pending" wording on your product puts the world on notice that the USPTO is in the process of examining your great idea (and hopefully will approve and issue a registration). If your application is rejected (or a year passes after your PPA is filed and you haven't filed an RPA), you should remove the "patent pending" tag. During this pendency period -- before the USPTO approves your application -- you cannot use patent law to stop others from making, using, or selling your invention. You must wait until the patent issues before you can chase infringers.
18 month rule. There is one twist: If your RPA is published (which usually occurs 18 months after filing the RPA) and the infringer is made aware of the publication, you can later sue (after the patent is issued) and collect damages for the period starting with the date of notification. In other words, you must write to an infringer and let them know that the patent is published and that you're coming after them once you get your registration.
Non-patent claims. Even though you cannot pursue the infringer under patent law, it's possible that you may have a claim that they copied your trademark or your copyrighted designs, or they used unlawful means to obtain your trade secrets.