by Randy Carey: 229.21(g) Record retention.
(1) A bank shall retain evidence of compliance with the requirements imposed by this subpart for not less than two years. Records may be stored by use of microfiche, microfilm, magnetic tape, or other methods capable of accurately retaining and reproducing information.
by John Burnett: There's no record retention requirement for deposit hold notices under Regulation CC, except for the exception holds placed under the "reasonable cause" provision under 229.13(e). For such notices, the record must include a brief statement of the facts given rise to the bank's reason to doubt the collectibility of the check. Under section 229.21(g), the records can be stored by use of "microfiche, microfilm, magnetic tape, or other methods capable of accurately retaining and reproducing information."
If the report you allude to includes the account number, amounts, dates, and reasons for the holds, and includes all section 229.13(e) holds, including the reasons behind "confidential info" statements, and it can be readily retrieved and interpreted, I think you're covered.
by Ken Golliher: Correct answers, both.
The difficulty comes when examiners/auditors want to review the accuracy of the holds. Your report may allow them to see the amount and length of the hold, but if you do not supply images of the checks how will they know it was right; e.g. the hold depicted is correct if it's a garden variety check, incorrect if it's a cashiers check?
Although not required except for "exception holds" banks oftentimes keep copies of hold notices along with copies of the checks deposited. It saves looking them up for examiners.