If the statistics for the column have been modified using optdiag, dbcc traceon(302) prints:
Statistics for this column have been edited.
If the statistics result from an upgrade of an earlier version of the server or from loading a database from an pre-11.9 version of the server, dbcc traceon(302) prints:
Statistics for this column were obtained from upgrade.
If this message appears, run update statistics for the table or index.