Retention Label

A retention label in Microsoft Purview is applied to individual files, emails, Teams messages, or other items and carries retention rules at the item level — keep for N years, then delete; declare as a record; trigger event-based retention. Different from retention policies, which apply at the container level (mailbox, site). Labels can be applied manually by users (a "Pick a label" button) or auto-applied based on content match (sensitive information types, trainable classifiers, keyword patterns). Records-management labels add immutability — items become unmodifiable and deletion requires disposition review. Auto-apply policies require Microsoft 365 E5 or specific Purview add-ons.