Submarine patent
A patent kept hidden in the application stage for years, surfacing only once the whole industry already depends on the technology.
Until 1995, US patent applications were secret and the term ran 17 years from grant, not from filing. Anyone who strung out the process with continuation applications could wait until the technology became standard and only then surface. The grandmaster was inventor Jerome Lemelson, whose machine-vision applications from the 1950s eventually earned over a billion dollars in licence fees, much of it from the barcode industry.
Aligning with TRIPS in 1995 made the term 20 years from filing, and since 2000 most applications are published after 18 months. In 2005 Lemelson's patents were held unenforceable for unreasonable delay. Unisys's LZW patent, enforced against users only after GIF had taken off, is often lumped into the same family.