Migration Set A migration set comprises a selection of objects (documents, folders) and set of rules for migrating these objects. A migration set represents the work unit of migration-center. Objects can be added or excluded based on various filtering criteria. Individual transformation rules, mapping lists and validations can be defined for a migration set. Transformation rules generate values for attributes, which are in turn validated by validation rules. Objects failing to pass either transformation or validation rules will be reported as errors, requiring the user to review and fix these errors before being allowed to import such objects.