https://en.wikipedia.org/wiki/Cadence_Design_Systems,_Inc._v._Avanti_Corp
Cadence sued Avant in December 1995, accusing it of stealing Cadence's software code, copyright infringement, conspiracy and other improprieties. ... Whyte ruled that Cadence's trade secret claim in the forthcoming trial against Avant was barred by a release signed by Cadence in 1994.Sep 10, 1999