The spelling of the word "xxix" is quite unique, as it consists of only four letters that seemingly make no sense. However, when looked at through IPA phonetic transcription, the meaning of the spelling becomes clearer. "X" represents the phoneme /ɛks/, which is commonly seen in words like "exit". "I" represents the phoneme /aɪ/, as in the word "eye". Finally, "ix" represents the phoneme /aɪk͡s/, which gives the word its final sound. Together, these three phonemes create the spelling "xxix".