"Siemens codes (SIE / 7346) are among the most reliably active corporate codes, showing 15–22% discounts at many global Marriott properties. The code appears in widely distributed PDF documents traceable to 2014. If you are caught, the property can raise your rate to the current rack rate and you could be considered to be defrauding the property. Wide documentation suggests this code has been in circulation for over 10 years."

"I occasionally try to get the corporate rate for a company I'm visiting in the area (for sales/consulting). Only once has a front desk clerk asked me to prove my eligibility, and she was satisfied by me giving the name and telephone number of the person I was visiting."

"I now always make it a matter of course to carry documents (business cards of my contacts, e-mails requesting my visit etc.) from my host company when I travel. This has always proven sufficient for the few times I've been challenged by the front desk clerk."