"FlyerTalk community specifically notes the MMM code as "the go-to code for the Minneapolis/St. Paul area, described as extremely reliable at local Courtyard and Residence Inn properties, with a low risk rating." One user documented using an IBM rate for 14 years at 80-100+ nights annually and "never once being asked for an ID." Another stayed 500+ nights and was never asked. The 3M code is regionally well-known near 3M's Minnesota HQ."

"GAP Inc's Marriott code GAP is listed in corporate code databases. No verification incidents documented in FlyerTalk or Reddit discussions. Clothing retail corporate codes at Marriott receive minimal attention from front desk staff — retail employee IDs are not standardized enough to be reliably verified. US domestic properties rarely verify retail-sector codes."

"I also use AAA if the corporate is not available. In 10+ years of using AAA I had never been asked to show the card until last month in FL at two different properties. One was a HGI in Palm Beach Gardens and the other a CY in Stuart. Stayed at both since on AAA rate and wasn't asked."