||Kim, Tae Sik & Oh, Young-il. (2021). An optimality-theoretic account of initial sound law in Korean, revisited. The Linguistic Association of Korea Journal, 29(3), 85-103. This paper investigates exceptions to Initial Sound Law in Korean within the framework of Optimality Theory. The law dictates that some nasal and lateral sounds not be in word-initial position. Even though a recent study (Oh & Kim, 2021) is able to cover fundamental cases of the law, many exceptions have still not been fully explained by the research, such as compounds, derivational words, proper nouns, numbers and bound nouns. Basically based on Oh and Kim (2021), we propose a revised constraint: a sonority difference between C and V in the initial position of a semantic unit should be at least 3 (CV SDiff (SUI ≥3)). With the notion of a semantic unit (instead of a word unit), the constraint interacts with other standard markedness and faithfulness constraints and clearly accounts for the limited distribution of the target sounds. The constraint ranking presented is as follows: *Complex (onset) ＞＞ Ident-IO (voice) ＞＞ CV SDiff (SUI ≥3) ＞＞ Max-IO ＞＞ Ident-IO (manner) ＞＞ CV SDiff (SUNI ≥3).