"ATK (Alliant Techsystems, now Northrop Grumman Innovation Systems) is a defense contractor. The Marriott code 259552 for ATK follows the defense contractor enforcement pattern: properties near major defense installations (Virginia, Utah, Minnesota) are more likely to verify. FlyerTalk's defense codes thread notes: "Defense contractor codes tend to face more questions at full-service properties near major installations." No specific ATK denial incident documented, but the defense sector calibration applies."

"I don't do mobile check-in if I'm wanting to upgrade. I check the app before I go in to see if any suites are available to book during the duration of my stay. If there is I just say "Would it be possible to get upgraded to an available suite with my platinum benefit?". Of course this is typically at the hotel that I stay in about once a month for 3 day at a time for work. The front desk pretty much knows me and know that I am fairly low maintenance."

"I think the generic 'show corp id' designation means show the company business card. I think a lot of us don't have them or, if we do & we're not going to an office that we'd need to show them, leave them at home. I worked for some F500s that didn't require corp ids with shiny smiling faces on them & others that did; same with company credit cards. All, however, provided biz cards when working for them."