The spelling of the word "COTSD" is a bit unusual, and can be confusing for those unfamiliar with its pronunciation. In IPA phonetic transcription, the word is spelled /kɑːtsd/. The first sound, /k/, is a voiceless velar stop. The second sound, /ɑː/, is a long vowel sound pronounced with an open mouth. The third sound, /t/, is a voiceless alveolar stop. The fourth sound, /s/, is a voiceless alveolar fricative. The final sound, /d/, is a voiced alveolar stop. Overall, the spelling of "COTSD" reflects the word's unique and specific pronunciation.