I guess on the Internets, you never release anything - it's released for you. Please be warned, (a) the doc is incomplete, (b) if you create an Urbit ship you'll eventually have to destroy it, as we don't have continuity yet.
Four-letter names that haven't been overexposed are hard to find. But four letters fits in a 32-bit direct atom, so the attraction is pretty irresistible.
Reminds me of how ITS limited filenames to six letters per component, because they used six bits per character and six times six is thirty-six bits, or one machine word.
To this day, HAKMEM ('Hacks Memo') is still called that: