SCO's crusade to gain rights over Linux has been dealt yet another blow by the National Retail Federation, which says the company's claims are "unfounded".

In a statement by the organisation, which represents more than 1.4 million US retailers, it was damning in its assessment: "Based on the information we have seen, the National Retail Federation believes the claims by The SCO Group are without merit. Novell is the last company that can demonstrate legal ownership of Unix System V."

The group's intervention was explained in a header. It read: "Within the last year, The SCO Group has claimed Intellectual Property rights to parts of the Linux operating system. Within the last few months, The SCO Group has threatened legal action against several major retailers for using Linux. The SCO Group claims that they hold the copyright to Unix and believes that retailers who use Linux violate SCO’s copyright."

It then piles into SCO's case: "In my opinion," wrote the organisation's CIO Dave Hogan, "it is almost as if The SCO Group’s business model is to generate a revenue stream through litigation. NRF expects that retailers who use Linux will survive the current litigation. The NRF CIO Council will continue to pay close attention to this issue."

SCO acquired certain rights to the Unix System V source code in 2002, but the question of exactly which rights remains unclear. Novell, which purchased the copyright from AT&T in 1993, claims it stills owns the Unix copyright.

Such a blunt assessment (and warning) makes SCO's legal endeavour look all the more precarious. Last week, DaimlerChrysler dismissed its particular lawsuit saying SCO had no rights whatsoever to demand what it was suing the company over. On top of this, the company that has provided SCO with much of its funding, BayStar, has asked for the money back claiming that it was misled.

SCO's "sue first and ask questions later" has seen it involve itself in court with several huge companies on an issue which remains extremely murky and on which only SCO stands to gain directly. It also goes against the interests of many thousands of other companies. Without exceedingly deep pockets its chances of success are growing slimmer by the day.