"different registers" means using different styles or levels of language depending on the situation or audience. It could refer to using a formal tone to speak in a professional setting, while using a casual tone with friends. Full definition
This juxtaposition suggests a cultural continuity in different registers of this belief in miraculous powers. (artlyst.com)
We have over 230 different registered dog breeds to choose from, making it easy to find the right puppy to suit your family. (puppiesanddogsforsale.com)
In a review of the exhibition, Mark Wallinger, the Turner Prize - winning artist who was a close friend, said:» He addressed the world in many different registers — sardonic, caustic, erudite and celebratory, with instinct, intelligence and wit.» (independent.co.uk)