It could be that the first interstellar navigators spoke Hawaiian, and they noticed that the language's 200 possible consonant-vowel-vowel (CVV) syllables would neatly divide the thousand-light-year thickness of the Milky Way's thin disk into five-light-year slices. In the galactic plane, they already used a logarithmic spiral coordinate system matching the pitch of the spiral arms. Combining Hawaiian's 40 CV syllables in pairs, they could conveniently divide the coordinate patch containing the Orion Arm into a 1600 × 1600 spiral grid. They could then specify a comfortably sized region of space with a three-word sector name like kai-hale-manu, lei-papa-hine, kui-lima-holo, kei-waha-wale, hoa-noho-lana, or pā-hana-mana.
As these examples show, sector name "words" were often actual Hawaiian words, and sector names would occasionally be evocative strings of words, or even phrases. This was good, on balance, because it often made sector names easier to say and remember. However, it also had some weird effects. For example, on the very rare occasion that a sector name was mistyped in a document, miscopied from a log, or misheard over a bad audio connection, there was a slight tendency toward errors that mistook nonsense words for sensible ones, ungrammatical phrases for grammatical ones, ugly names for beautiful ones, boring names for funny ones, and scary names for auspicious ones. This affected migration patterns over time. The wū slice of the disk also took on an air of mystery, since wū was the only CVV syllable that never occurred in any Hawaiian word.