Hanja-mal or hanja-eo is about words which can be written with hanja . Hanmun ( í ë ) is about the Chinese Classical writing , but hanja can sometimes be used to generally mean hanmun too . Hanja-mal or hanja-eo refers to words which can be written with hanja , and hanmun refers to Classical Chinese writing , although `` hanja '' is sometimes used loosely to encompass these other concepts .