(5)To protect investors and preserve market stability during periods of stress or unusual redemption activity, a UCITS may activate the extension of notice periods. Depending on the investment objective and redemption policy of the UCITS, the extended notice period may be a specific number of days, weeks, or months, or a fixed date preceding the redemption date. Where appropriate to the investment strategy and redemption policy of the UCITS, the minimum notice period that investors should give to a UCITS when redeeming their units or shares may be equal to zero. In that case, the UCITS should still be able to select and, where appropriate, activate the extension of notice periods by extending the period of notice beyond the zero notice period.