defclass HistoryControl {
                NRECORD,		;; Number of records
                Date,			;; Base creation date
                Verbosity		;; Verbosity control
  }

defclass HistoryRecord {
                Creator,		;; Creator of new record
                Date,			;; Date of history creation
                Host,			;; Machine on which it was done
                Text			;; The history text
  }