AI generated answer (using internal Slack threads):

The 'Allow Non G/L Changes' permission in NetSuite allows a user to make non-General Ledger changes to a period. This includes changes that do not affect the financials of the period, such as updating a Purchase Order number on an invoice from a closed period. However, this permission works in conjunction with the 'Allow Non G/L Changes' checkbox in the period management. Even if a user has the permission, they won't be able to make changes unless the checkbox is ticked for the specific period. On the other hand, the 'Override Period Restrictions' permission allows a user to post to a period that has transactions locked but is not closed, and also allows making Non-G/L changes when the feature is active on a period. In 2021.2, there was an enhancement related to the 'Allow Non G/L Changes' permission which might have unchecked previous periods. However, it is possible to re-enable it for the periods. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******