From Bulbapedia, the community-driven Pokémon encyclopedia.
A Pokémon Sommelier (Japanese: ポケモンソムリエ Pokémon Sommelier) is a Pokémon Trainer who specializes in identifying the compatibility between Pokémon and their Trainers, much like how a real Sommelier identifies the compatibility between wines and various foods. They use their knowledge and experience to diagnose the bond between Trainer and Pokémon, and from there give advice on how to strengthen that bond.
A ranking system for Pokémon Sommeliers was revealed in BW019, with four different ranks; S, A, B, and C, where S is the highest rank and C is the lowest. Cilan is revealed to be an A-rank Pokémon Sommelier.
- Pokémon Sommeliers are not well-known outside of the Unova region.