Currently the tags for the Pokémon anime series based on each generation of games are as such:
pokemon_rgby - pokemon_(classic_anime)
pokemon_gsc - pokemon_(classic_anime)
pokemon_rse - pokemon_ag
pokemon_dppt - pokemon_dp_(anime)
pokemon_bw/pokemon_bw2 - pokemon_bw_(anime)
pokemon_xy - pokemon_xy_(anime)
pokemon_sm/pokemon_usum - pokemon_sm_(anime)
This is, I imagine, to mimic the practise of the game tags using each game in a generation's initials - for example, the seasons for pokemon_rse were tagged pokemon_ag as they are officially titled Pokémon Advanced Generation. Though the three most recent anime tags were also made using the official anime titles, they match the initials for the games these seasons are based off of which gives the impression that the naming convention is actually "pokemon_game_(anime)".
To remove potential confusion relating to the tags and to introduce some consistency, I'd like to suggest changing pokemon_ag and pokemon_dp_(anime) to pokemon_rse_(anime) and pokemon_dppt_(anime). They're not 100% factually correct, but they're much more intuitive and easy to use. pokemon_ag especially needs to change, as without even an _(anime) qualifier it looks to be another game tag at first glance.
I'm fine with the pokemon_(classic_anime) tag staying as it is though, because that series covers two generations of games at once and changing it to pokemon_rgby/gsc_(anime) just seems silly.