# Document revisions To be notified about updates to this whitepaper, subscribe to the RSS feed. | Change | Description | Date | | --- |--- |--- | | [Updated best practice guidance](#document-revisions) | Best practices were updated with new guidance in the following areas: SUS 1, SUS 3, SUS 4, SUS 5, and SUS 6. Guidance has been improved across these best practice areas. SUS 6 received a new best practice, SUS06-BP01 Communicate and cascade your sustainability goals. Existing best practices in SUS 6 have been renumbered. | November 6, 2024 | | [Updated best practice guidance](#document-revisions) | Small changes throughout the pillar. | June 27, 2024 | | [Updated risk levels](#document-revisions) | Minor updates to best practice risk levels. | October 3, 2023 | | [Updated best practice guidance](#document-revisions) | Best practices were updated with new guidance in the following areas: [Alignment to demand](https://docs.aws.amazon.com/wellarchitected/latest/sustainability-pillar/alignment-to-demand.html), [Software and architecture](https://docs.aws.amazon.com/wellarchitected/latest/sustainability-pillar/software-and-architecture.html), [Data](https://docs.aws.amazon.com/wellarchitected/latest/sustainability-pillar/data.html), and [Hardware and services](https://docs.aws.amazon.com/wellarchitected/latest/sustainability-pillar/hardware-and-services.html). | July 13, 2023 | | [Updated for new Framework](#document-revisions) | Best practices updated with prescriptive guidance and new best practices added. | April 10, 2023 | | [Whitepaper updated](#document-revisions) | Best practices updated with new implementation guidance. | December 15, 2022 | | [Whitepaper updated](#document-revisions) | Best practices expanded and improvement plans added. | October 20, 2022 | | [Initial publication](#document-revisions) | Sustainability Pillar - AWS Well-Architected Framework published. | December 2, 2021 |