LOTA LOTUSOne of the more problematic things about registering trademarks in Korea is the Korean pronunciation. When one registers an English word as a trademark in Korea, they receive protection for the implied Korean language pronunciation of that brand. The problem is the Korean Intellectual Property Office, its Tribunal, and the Patent Court have can have very odd (and inconsistent) interpretations of how English marks are pronounced in Korean. Further problematic is that Korea tends to give the benefit of the doubt to applied trademarks that could only arguably have a different pronunciation from a registered brand. Take the case of Hyundai Motor v. Lotus Group.
Hyundai applied for the mark LOTS, which was objected to by Lotus, owner of the registered mark LOTUS. In Korean "Lotus" would commonly be pronounced "Ro-Tu-Su". LOTS however would normaly be prounced "Rot-su", however arguably one could pronounce this "Ro-ti-su". True to form, the Patent Court gave Hyundai the benefit of the doubt, and cleared the way for registration of LOTS.
It is for reasons such as this that wise for companies, especially foreign ones, that they identify and register possible Korean homonyms and other arguably similar marks. There are no hard and fast rules to identify such, and you may even be mistaken on some, but businesses should be aware of it. Most problematic in my experience has been the pronunciation of individual letters (such as the above) and the "L/R" sound at the end of syllables. That sound may be the best way to recreate the english, but in everyday Korean the sound is normally dropped and thus technically creates a new name in Korea.
In another issue in the Hyundai case, the Patent Court ruled that Lotus is NOT a famous worldwide brand. I can not say it strongly enough, "You know what you call a company relying on its worldwide fame in Korea? One that gets screwed.". In general if you do not have substantive sales in Korea using that brand, your chances of proving worldwide fame reduce substantially (its possible, but I wish you luck). This is why it is recommendable not only to file under the Madrid convention (which gives you some protection), but also to register your key brands in Korea, regardless of actual use (there are further problems with this tactic, but it will give you some protection).