BT's court case against ISP Prodigy Communications over the hyperlink patent will begin on 11 February 2002 in New York. BT is claiming unspecified damages for alleged infringement of its patent, which covers the basic navigation method on which the Web is built. If BT wins it is likely to pursue other ISPs for licence fees. Prodigy was the first commercial ISP when it launched in 1984, the first consumer online service to offer World Wide Web access and the first to offer its members the ability to publish personal World Wide Web pages. It now claims to have more than 3.5 million customers. BT contacted Prodigy and 16 other ISPs, including America Online, in June 2000 asking them to buy a hyperlink licence. BT has not indicated what it would charge if it wins its case, but any costs would be likely to be passed on to business and consumers who have Web sites. The patent, number 4,873,662, was issued to BT in America in 1989 and expires in 2006. The company said it only discovered the patent in a routine trawl through its own patents four years ago. But the priority date for the patent is July 1976, which means that for the patent to be successfully challenged a company must show prior art before that date, according to Gregory Aharonian, editor of the Internet Patent News Service and a vocal critic of what he calls poor-quality patents. Ahoronian believes that several papers relating to hyperlinks, published in the 1960s, will "come back to haunt BT's efforts". One of these papers was on a hypertext editing system for the IBM 360, delivered at the Illinois Conference on Computer Graphics in 1968, which showed how "any text structures may be (linked) in arbitrary ways, and the user may jump along connections in this linkage structure." Ahoronian also points to a video of a demonstration delivered by Douglas C. Engelbart who had been working with a group of 17 researchers in the Augmentation Research Center at Stanford Research Institute in Menlo Park, California. In a live demonstration of the online system called NLS, which the researchers has been working on since 1962, Englebart demonstrated the ability of NLS to jump between levels in the architecture of a text, making cross references, creating Internal linking and live hyperlinks within a file. For everything Internet-related, from the latest legal and policy-related news, to domain name updates, see ZDNet UK's Internet News Section. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Telecoms forum. Let the editors know what you think in the Mailroom. And read other letters.