According to Foresight News, Aptos has announced the approval of AIP-91, which introduces the Enum type in the Move Virtual Machine (VM). This new feature will enable developers to define structured data with multiple variants, enhancing code readability and maintainability. The Enum type also supports efficient data structures and allows for version control, enabling data to evolve over time without breaking compatibility. This advancement is expected to facilitate long-term smart contract management without requiring changes to the underlying storage or serialization.