Hangul Jamo is a Unicode block containing positional (Choseong, Jungseong, and Jongseong) forms of the Hangul consonant and vowel clusters. They can be used to dynamically compose syllables that are not available as precomposed [BLOCK:hangul-syllables Hangul syllables] in Unicode, specifically archaic syllables containing sounds that have since merged phonetically with other sounds in modern pronunciation.