In a decision on refusal of entry or deportation, which does not include a prohibition of entry, a third-country national is given a period of at least seven and a maximum of thirty days during which [..]

An administrative procedure whereby an individual agrees to be deported. No legal bar to reentry is imposed.  

In practice, and more often than not, so-called “voluntary” return stems from an explicit or implicit pressure exerted by a state authority on a migrant, even if the Council of the European Union defines voluntary return as “the assisted or independent departure to the country of origin, transit or another third country based on the will of the ret [..]