It is a term that is often applied without distinction between providers to refer to any wireless internet connection but an application to register the word WI-FI has been registered by the Wireless Ethernet Compatibility Alliance (now the Wi-Fi Alliance). This application came under challenge from Wilhelm Sihn Jr KG, the holder of an earlier mark in the word "WISI" that had been registered in respect of Class 9.

Wilhelm Sihn Jr KG argued that there was a likelihood of confusion on the part of the public and that the application should be rejected under s5(2)(b) of the Trade Marks Act 1994.

The hearing officer held that the marks were not similar and there was in fact no likelihood of confusion between the marks.

Wilhelm Sihn Jr KG appealed but was unsuccessful. The Appointed Person held that the hearing officer had been wrong to find that the marks were not similar but upheld the finding that there was no likelihood of confusion.

The grant of this trade mark should give companies cause to consider their use of the term Wi-Fi and the possibility that such use may be in contravention of a registered mark. We suggest that the Wireless Ethernet Compatibility Alliance will have to maintain a active policy of defending its mark if it is to resist it "failing into the public domain".