"I have used that code for this hotel more than once and have never been asked for any more ID than my driver's license."

"Costco's Hyatt code (66267) is a Costco member discount, not a Costco employee code. FlyerTalk discussion: "Costco Travel arranges negotiated rates for Costco members — this is a published membership rate, not a confidential corporate employee benefit." Costco members must show membership card at check-in, not an employee badge. The verification risk is minimal: Costco membership is easy to obtain and the card is easy to carry."

"AAA (alt 2) Hyatt code (15985) is another secondary AAA membership discount code at Hyatt. AAA rates are publicly advertised and require only showing an AAA membership card. FlyerTalk documents: another reported being asked only twice in 70-80 stays. AAA rates are typically 5-15% off, reducing hotels' incentive to verify. The secondary code designation suggests it may be for specific Hyatt properties or booking channels with even lower enforcement than the primary code."