The spelling of the word "OCTAW" is based on the phonetic transcription of its pronunciation in International Phonetic Alphabet (IPA). It is spelled as /ˈɑːktɑː/, where the first sound is an open back unrounded vowel, followed by a voiceless velar plosive and the second sound is the same vowel again. The final sound is an unvoiced alveolar stop. The IPA gives accurate and precise representations of speech sounds, allowing for standardized spelling of words like "OCTAW".