They don't have an equivelent for it. The romanisation is only there to make it "easier" for people to pronounce, even though it's not always a great idea to go by romanisation. Personally I hate using romanisation when learning others alphabets.

I think you are making the basic mistake here thinking Korean uses a sign system like Chinese. It does not. Hangul is a phonetic system. There is also Hanga, which is the Korean sign system, but that was replaced by Hangul hundreds of years ago or something. There is romanization of Hangul, but then you just replace one phonetic system by another. (Like you would do when writing Russian letters or Arab letters in Latin letters. Personally I think romanization sucks, since it does not tell you exactly how the pronunciation is and also because it is based on the English spelling. And sorry to say it to you as a native English speaker, but English spelling sucks to begin with. It has the most inconsistent spelling of all the Indo European languages I know. Korean romanization only confuses you.

I don't think we have such characters. We only use '한글' only.

Hello Rosco. How are you? The word you are looking for is termed "Transliteration". The same technique can be applied to almost any language I think. ---Warm Regards, Bruce

thanks @maricormondares