espocrm-base/application/Espo/Resources/metadata/app/linkManager.json

{
    "createHookClassNameList": [
        "Espo\\Tools\\EntityManager\\Link\\Hooks\\TargetListCreate",
        "Espo\\Tools\\EntityManager\\Link\\Hooks\\AssignedUsersCreate"
    ],
    "deleteHookClassNameList": [
        "Espo\\Tools\\EntityManager\\Link\\Hooks\\TargetListDelete",
        "Espo\\Tools\\EntityManager\\Link\\Hooks\\ForeignFieldDelete"
    ]
}