USPTO Seal As of March 16, 2013 the PTO stopped accepting or reviewing applications for SIRs.  Before March 16, the SIR was a technique to notify the world of an invention that the invention owner did not wish to patent.  The effect of the SIR was to dedicate the invention to the public so that anyone could make, use and sell the invention and no one could file a new patent application for it.   SIRs became largely redundant when the U.S. moved to the system of publishing utility patent applications eighteen months after filing.

— Robert Yarbrough, Esq.