The bulk update request #12535 has been approved by @nonamethanks.
create alias delinquent_squatting -> slav_squatting
create alias yankee_squatting -> slav_squatting
Utility alias, since the main tag for "Slav squatting" in Japanese is "ヤンキー座り" which literally means "Yankee/Delinquent squatting". Plus the tag existed before Slav squatting became widely known.