Napster won a slight reprieve yesterday, despite District Judge Marilyn Hall Patel issuing an injunction against the company.

Patel's injunction requires Napster to, in effect, continue with the blocking mechanism the company put into place on its file-sharing service Sunday night.

The injunction goes against the wishes of the Recording Industry Association of America (RIAA). It places the burden of notification of copyright abuse onto the recording industry.

Blocking proof The RIAA - and its members - must provide four things to Napster in order to get songs blocked: the title of the work to be blocked, the name of the artist, one or more filenames the song is available as on Napster, and certification the song is the plaintiff's work.

Napster will then have three business days to "prevent such files (identified by the plaintiffs) from being included in the Napster index". In this case, Napster would use its "screen" to prevent other users being able to see the specific file in any database, thereby making it impossible to download.

Malcolm Maclachlan, electronic media analyst with International Data Corporation (IDC), said: "I certainly don't think the blocking has been very effective so far, people are already getting around it."

Back to court? Maclachlan questioned whether this would protect Napster against future liability. "I wonder what happens if the recording industry goes back in a few months and says it doesn't work," he said.

Judge Patel also stated in the ruling that the two sides must work together in "identifying variations of the filenames, or of the spelling of the titles or artists' names" of the songs in question.

"If it is reasonable to believe that a file available on the Napster system is a variation of a particular work or file identified by plaintiffs, all parties have an obligation to ascertain the actual identity (title and artist name) of the work," the ruling said.

The injunction is a middle ground between the proposed injunctions drafted by Napster and the recording industry, and adheres to what Judge Patel implied she would do when both sides appeared before her at a hearing last Friday.

The burden of ensuring no copyrighted work is transmitted over Napster is shared between the industry and Napster, with the industry having "to provide notice to Napster" and Napster being responsible for "policing the system within the limits of the system".