When is a worker not a worker? When they’re an “independent supplier,” says UK takeout service Deliveroo. This is according to the company’s vocab “crib-sheet,” which features a six-page list of dos and don’ts, guiding staff on how to talk about the business.

The internal document was seen by a number of publications, and makes for some awkward reading. It says bicycle couriers who work for Deliveroo are never to be referred to as workers, employees, or staff, and that the Deliveroo jackets they have to wear on the job are not uniforms but “branded clothing.” These workers don’t have “contracts,” says the document, but “supplier agreements.” They don’t “schedule shifts,” but “indicate their availability.” And they can never get sacked — instead, they’re “terminated.”

A spokesperson for Deliveroo said: “We have almost 1,000 full-time staff and work with over 15,000 riders in the UK. We ensure that employees know how to work with our partners, which includes training and guidelines to follow when talking to customers, restaurants, and of course self-employed riders.”

But the contortion of language in this document shows how wary Deliveroo is of presenting itself as a regular employer. Like Uber, Deliveroo’s business model relies on access to a flexible supply of labor, to which it doesn’t owe employment benefits like sick pay and holidays. And, as with Uber, this arrangement is being challenged.

In the UK, politicians have criticized both Deliveroo and Uber for their business practices. The language they use in their dealings with workers has also came under fire, with one MP describing Uber’s contracts as “gibberish” and “almost unintelligible.” (Uber responded to this criticism by saying: “We recognize our terms could be written in plainer English and we started the process of revising them some time ago.”)

Currently, Deliveroo’s riders are treated as self-employed contractors in the UK, but this could change with a pair of ongoing legal challenges. In one, a group of London couriers are demanding union recognition from Deliveroo; and in another, a separate group are demanding workers’ rights including holiday pay and minimum wage. Uber lost a similar challenge last year, which it’s currently in the process of appealing. Deliveroo could be next, despite its dos and don’ts.