I treated yellow squares as two sequential rules: (1) regex with [A-Z] character classes less the characters you know are not in the exact spots -- this certifi

I treated yellow squares as two sequential rules: (1) regex with [A-Z] character classes less the characters you know are not in the exact spots -- this certifies you've eliminated the characters that shouldn't be there. These can be directly encoded into a single SQL query; (2) a series of in operators to check that the character is there at all. In SQL this could be `word LIKE '%S%'` after the initial (1) rule.