The spelling of the word "CTDKI" may seem unfamiliar to most people. However, it can be deciphered using the International Phonetic Alphabet (IPA) transcription system. The letters "C" and "K" represent the same sound, which is the voiceless velar plosive /k/. The letters "T" and "D" represent two different sounds, the voiceless alveolar plosive /t/ and voiced alveolar plosive /d/, respectively. Finally, the letter "I" represents the vowel sound /ɪ/. Therefore, the proper pronunciation of "CTDKI" would be /ktdki/ or "k-t-d-k-i".