I stumbled upon the [proprietary] code somewhere here on FT, but it is returning rates of $89 at the f/s Marriott where I would like to stay when the property is $149 per night without the [proprietary] code.

Is this a code that can be used by Delta medallions/customers, or is it exclusively for employees? I read the fine print, and it doesn't say anything about needing to be an employee or having to show proof of eligibility, but nearly half off just seems too good to be true.