Crossword-Solution: PPO 3 letters, 15 clues 🏆 scrabble score: 7

Definition: A situation is _Properly_ Pareto Optimal (PPO) compared to an alternative iff it would be PO when some conditions are properly defined and interpreted - while it seems non-PO when these conditions are ill-defined and wrongly interpreted.

The _Céppo_, or Yule-log, is lighted at two o'clock the day previous to Christmas, on the kitchen hearth in provinces where it is sufficiently cold to have a hearth, and fires are lighted in other rooms, for here as elsewhere fire and light are necessary adjuncts of Christmas.

From their sun-worshiping Aryan ancestors Italy derives the custom of burning the _céppo_, the love of light and fire, and many other customs.

Visits and some presents are exchanged among friends, dinner parties, receptions, and fêtes of all kinds are in order, but all interest centers in the church observances until Epiphany, or _Bafana_, as Italians term it, when children hang up their stockings, _céppo_ boxes are exchanged, and people indulge in home pleasures to some extent.

The only point of agreement is in the first personal pronoun, “I”; this is “nga-nga” on the Swan River; “nga-toa” in New South Wales; “nga-ti,” Adelaide; “ngai-tyo,” Mount Barker; “gni,” Murchison River; “nga-pe,” Encounter Bay; “ngai,” Port Lincoln; “nga-ppo,” Murray River; “naddo,” Murrumbidgee River; “nga-pe,” Lower Murray; “noga-toa,” Hunter River.