Reports shall be prepared (1) upon completion of the original provisional period, (2) at least on an annual basis with the date to be determined by the local office, (3) as a subsequent report after the issuance of a report of performance less than satisfactory (such subsequent report may not be done less than 90 days after the previous report), and (4) on occasions when the supervisor desires to record performance worthy of recognition, either favorable or unfavorable. Reasons for submission of this type of report shall be explained in the report.