Technical references, pre-calculated points-plus-cash costs, and booking workflows for airline loyalty redemptions and booking URL engineering. Covers British Airways Executive Club Avios (UK-origin), Qantas Frequent Flyer and Amex Membership Rewards (Australia-origin), and Finnair deep-link JSON URL construction. Use when planning or pricing award flight redemptions, comparing carrier surcharges, checking reward availability, or generating Finnair booking URLs.
