Editorial note is a note going on a special log, and the notes are being posted above the articles. The notes can be removed by a simplified interface accessible to the administrators, and added by users with sufficient rights. The notes can be preformatted.
A primary reasoning behind editorial notes are to be able to mark articles without interfering with an editors on-going work.
To be able to filter out specific articles the log entries should be searchable somehow. It should also be possible to refer both sections in the subject page and on the discussion page.