| It actually appears that C-3P0 is the correct spelling and hyphenation of the name. Artoo Detoo is written as such, and hyphenated R2-D2. See Threepio is written out this way; logically, following the same hyphenation rules, it would be writen, numerically, as C-3P0.
Also, in the novelizations, when it's written numerically, and even on the *official* website, www.starwars.com, it's C-3PO.
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