A PureNomic is one that began with PeterSuber's initial ruleset (PeterSuberNomicRuleset).
Or so says whoever started this page. But I've never seen the term used except in reference to a Nomic that begins with Jacob Davenport's PureNomicRuleset, which is, in full, 'All players must agree to any changes to the game.' -- RichHolmes
I would call the above (PeterSuber) variant VanillaNomic? instead of PureNomic. -- Elysion