The war of the Apples in the High Court (the Beatles’ Apple Corps v Apple Computer Inc) highlights the failure of intellectual property agreements to account for technological advancements. The purpose of a trademark is to distinguish one person’s goods or services from those of others. Nevertheless, it happens that two – and sometimes more – traders end up using the same brand. At least three companies happily use Polo as a name for their product without the public ever becoming confused about whether their packet of mints were made by Ralph Lauren or Volkswagen.

The advent of the internet and the use of domain names, however, has led to turf wars between the owners of trademarks that previously coexisted happily. Converging technology has also put old arrangements under strain. The first of these developments resulted in litigation involving arrangements between Pitman Publishing and Pitman Training (Pitman Training Ltd v Nominet UK (1997)) and has reignited a long-running standoff between the Worldwide Fund for Nature and the World Wrestling Federation (2002). The second development has brought into question the old arrangements between the Beatles’ record company and the computer manufacturer with a similar name.

In the Pitman case, the problem manifested itself in a dispute over who was entitled to the domain name ‘pitman.co.uk’. When the businesses passed into different ownership years ago, an agreement was written to govern the use in their respective fields of the name. Had the authors of the agreement in 1985 foreseen the development of the internet and domain name system, they might have legislated for it; but of course they could not and did not.

Now, the carefully-drawn agreement between the two Apples, which has already provided several contributions to the law reports, has run into trouble as the computer company has found itself – thanks to the hugely successful iPod and its associated iTunes downloading service – becoming part of the music industry.

Coexistence agreements are not uncommon in the trademark world. They are part and parcel of overcoming objections to registration that are raised by the Trade Marks Registry and opposition from third parties who own conflicting rights.

These recent developments illustrate the simple fact that an agreement cannot remain valid for ever. The Apples’ 1981 agreement appears to have been indefinite, and other things being equal one would expect a trademark delimitation agreement to last forever. Having agreed at the outset not to use the mark in the other organisation’s field, one would expect that obligation to last forever unless the other organisation stopped using its trademark.

But, of course, other things are rarely equal. Over time the neat line drawn between computer goods and services and what the agreement referred to as “Apple goods and services” (Apple Corps being, as it were, the senior Apple) has not only blurred, it has been erased altogether. Computers are now intimately concerned with records, music and entertainment – basically, the Apple goods and services.

Unless the Apple Corps trademark had fallen out of use over the past five years (its CDs are still being published on the Apple label, in the UK at least, so non-use cannot realistically be an issue), the agreement presumably remains in force. Which, from the Beatles’ perspective, is how it should be: trademark owners do not want to be revisiting complicated arrangements about the use of the mark with any degree of frequency. The junior users, on the other hand, would no doubt wish to be able to reopen negotiations from time to time.

The lesson for everyone involved in trademarks must be to try harder than ever to avoid this sort of conflict. There is not an infinite number of trademarks in the world, but there is a large stock; no one obliged the computer maker to adopt the name it chose; and businesses should not satisfy themselves with merely being able to put enough clear blue water between their brand and others’ to satisfy the Trade Marks Registry. That water might turn out to be green and murky in a few years’ time.