The following schemas
PageCreation PageDeletion PageMove PageRestoration ServerSideAccountCreation Edit Popups
possess one or more fields that contain user-inputed textual data and which are not auto-purged after 90 days.
This kind of data is sensitive by itself and should not be published as part of any dataset. So, it will be good to have that marked in the schema page, so that people who are planning to extract or release EventLogging data from those schemas will know.