All, I opened https://issues.apache.org/jira/browse/TIKA-4794 to discuss potential further changes to metadata keys that would add further consistency and principles for naming metadata keys in 4.x. These would be breaking changes in 4.x. If we went with options 2 and 3, I think we'd want a 4.0.0-beta-2 release. Please let me know what you think.
Best,
Tim
