This redaction is part of the License Change process. For background reading regarding the license change, please see http://www.osmfoundation.org/wiki/License/We_Are_Changing_The_License

Any old versions of node, ways or relations that contain information that we can no longer publish will be hidden.

This redaction contains versions calculated as :visible by the bot. This doesn’t mean that the version should actually be visible, just that in future, there is the potential for some aspects of the version to be shown.