Permits for Low-Emission Zones (LEZ)
A complying vehicle wanting to enter the LEZ often has to identify itself as complying with the standards, either by showing a sticker, or being on a database (usually automatically on a national vehicle database plus those actively registered (foreign) vehicles that are not on the national database). These are not seen as permits, but stickers or registrations. (see also Exemptions for Low-Emission Zones)