Britain’s Advertising Standards Agency (ASA) has struck down a complaint about Siri, the personal assistant software on the iPhone 4S. The frustrated iPhone owner complained that Siri was not able to direct him to businesses in his area, despite advertising that, he said, suggested it would.

The ad in question was for Britain’s Vodafone mobile carrier, and focused on some of Siri’s unique capabilities. Here’s the text of the ad:

Simply ask Siri to help you send messages, set reminders or search for information. It understands not only what you say but also what you mean, so you can speak naturally. It can even use information from your iPhone – such as your location, contacts, and contact relationships – to provide intelligent, personal assistance.

A disclaimer on the ad emphasized that “Siri may not be available in all languages or in all areas, and features may vary by area.”

The complainant felt that this ad was misleading, as it failed to make Siri’s limitations in the UK sufficiently clear. Since the actual ad copy came from Apple, not Vodafone, the carrier deferred their defense to Apple. Apple insisted that the ad was not misleading and that Siri does use certain location services in Britain, but that the ad does not say or imply that users in the UK can use Siri to look up business. Apple also said that they had carefully avoided using map images in their British advertising for Siri, in light of the fact that Siri does not have access to map data in the UK.

The ASA agreed with Apple that the ad did not suggest that Siri could do things it couldn’t in the UK. The ASA ruled that it was neither Apple’s nor Vodafone’s fault if British iPhone users construed advertising in the UK based on their knowledge of what Siri can do in the U.S.

Siri’s capabilities – or lack thereof – has caused frustration for iPhone users. While the implementation of Siri on U.S. iPhones is generally quite good, the personal assistant software is notoriously bad with accents. Speaking U.S. English with a foreign accent (or U.K English with a Scottish accent) causes all sorts of problems ranging from the hilarious to the infuriating.

Is the ad misleading? Is Apple (or the carrier) responsible for making it clear just what Siri can and can’t do in a given country? Let us know what you think in the comments.