Bolivian Spanish word
casero / casera
Meaning: warm address between a regular customer and 'their' vendor
How it is used in Bolivia
The vendor calls you 'casero' and you answer 'casera', it means roughly 'my regular'. Using it back is friendly and stays polite; you keep the usted register, never vos.
Learn it in a real situation
Food, Restaurants and Dietary Needs in Bolivia, Spanish