Non-rev (aka non-revenue) refers to the industry practice of free or reduced-rate travel for company employees, their close family and those within the industry. Some carriers provide this service at no cost to the benefit holders, while others charge a small fee, usually no more than $50, depending upon class of service and distance traveled.
Also, the vast majority of carriers have agreements in place that allow employees and their families from another company to "non-rev" on their flights, despite any marketing competition. For example, a UA
flight attendant could non-rev ORD
Many companies also provide what are called buddy passes or friends and family certificates whereby the employee can give "non-rev" opportunities to friends or extended family on a trip-by-trip basis. These passes are limited in number ranging from the pathetic 8 at DL
to upwards of 30+ at UA
In all of the cases, the "non-rev" is at the bottom of the standby list. All revenue passengers are boarded, followed by company non-revs then others.
Ignorantia juris neminem excusat.