base
Each candidate hashes the word before it with a 64-bit little-endian counter appended: sha256( word ‖ counter ). zero seeds the chain.
ascii8
One byte per character. A match means the SHA-256 hash prefix spells the word in ASCII hex.
targets
one through twelve — each word ground from the one before it, each successively longer prefix match kept on the way to the full word.
counters
Winning counter values from 10 million to 52 trillion, within a 248 budget per search.