Revision as of 23:31, 17 May 2017 edit 86.147.207.132 (talk) →See also: fmt ← Previous edit		Revision as of 09:16, 18 February 2018 edit undo 142.254.60.237 (talk) →Patent issues Next edit →
Line 21: == Patent issues == Tornado codes are patented inside the United States of America.<ref>{{harv\|Mitzenmacher\|2004}}</ref> Patents US6163870 A (filed Nov 6, 1997) and US 6081909 A (filed Nov 6, 1997) describe Tornado codes, and have expired as of November 6, 2017. Patents US6307487 B1 (filed Feb 5, 1999) and US6320520 B1 (filed Sep 17, 1999) also mention Tornado codes. Patents are currently valid until 20 years after filing, and since '370 A and '909 A have both expired, a case can be made that tornado codes are no longer patent encumbered. == Citations ==

Tornado code: Difference between revisions