"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."

"I can say, with absolute certainty, I've never been asked for a Corporate ID: only a business card. Despite working for a company towards the top of the F50 list, I am a remote employee. Remote employees are not given IDs in our company. When I do have to go to the office, I need to get a guest ID."

"I have never been asked (yet) at Marriott but usually I show up at the desk by handing over ID/credit card. Don't read this as me endorsing going crazy using the codes that you aren't supposed to use! Interesting about the client reports going back daily."