Companies are NOT required to mark their product with patent numbers, but if they do they can demonstrate willful infringement on the patent if you decide to copy the product.

Edit: Acutally from 35 U.S. Code § 287 http://www.law.cornell.edu/uscode/text/35/287

In the event of failure so to mark, no damages shall be recovered by the patentee in any action for infringement, except on proof that the infringer was notified of the infringement and continued to infringe thereafter, in which event damages may be recovered only for infringement occurring after such notice

Companies are NOT required to mark their product with patent numbers, but if they do they can demonstrate willful infringement on the patent if you decide to copy the product.

Edit: From 35 U.S. Code § 287 http://www.law.cornell.edu/uscode/text/35/287

In the event of failure so to mark, no damages shall be recovered by the patentee in any action for infringement, except on proof that the infringer was notified of the infringement and continued to infringe thereafter, in which event damages may be recovered only for infringement occurring after such notice

Companies are NOT required to mark their product with patent numbers, but if they do they can demonstrate willful infringement on the patent if you decide to copy the product.

Companies are NOT required to mark their product with patent numbers, but if they do they can demonstrate willful infringement on the patent if you decide to copy the product.

Edit: Acutally from 35 U.S. Code § 287 http://www.law.cornell.edu/uscode/text/35/287

In the event of failure so to mark, no damages shall be recovered by the patentee in any action for infringement, except on proof that the infringer was notified of the infringement and continued to infringe thereafter, in which event damages may be recovered only for infringement occurring after such notice