Stephen Colbert (courtesy of NPR) explains the meaning of backsies thus:

Mr. COLBERT: Backsies is the technical term for reneging on a previously settled agreement.

(Soundbite of laughter)

Mr. COLBERT: We've all done backsies, asking for the return of your Barbie doll or baseball card. In fact, 50 percent of all American marriages end in backsies.

Today Blawgletter learned that patent law doesn't like backsies either (okay, we learned that a Some Time Ago, but play along).

For on this day the Federal Circuit — that enforcer of inventions, that protector of patents, that 50+ percent reverser of Markman rulings — held that a patent holder went too far when it tried to "recapture" stuff it cast aside while trying to wheedle needle patents from the U.S. Patent and Trademark Office.

The holder's gambit came via its request to cancel and then reissue a patent on a design for a syringe that protects against needle sticks.  Under 35 U.S.C. § 251, you can use the reissue process to enlarge "the scope" of the original patent if you "through error without any deceptive intent" claimed "less than [you] had a right to claim in the patent".  You can ask for reissue up to "two years after the grant of the original patent."  Id.

But you can't claw back scope that you gave up the first time around.  In MBO Laboratories, Inc. v. Becton, Dickinson & Co., No. 08-1288 (Fed. Cir. Apr. 12, 2010), the court ruled that MBO broke the rule against backsies.  MBO had told the examiners in two patent prosecutions that its invention prevented needle sticks by retracting the needle instead of pushing a "guard body" over an unretracting needle.  "Because MBO surrendered a guard body that moved forward to cover a fixed needle and sought to reclaim relative movement in its reissue claims, MBO violated the rule against recapture."  Id. slip op. at 15.

The panel also noted that "[i]ndividuals, not corporations, create inventions".  Id. at 4 n.1; but see Citizens United v. Federal Election Commission, No. 08-205 (U.S. Jan. 21, 2010).