It was not improper for the accused solicitor, when he received a requirement under s. 232(3.1) to produce client documents within 30 days of the letter, to return documents for which he claimed solicitor-client privilege to the client. The phrase "about to" in s. 232(3.1) requires that a Revenue officer be physically present when documents for which solicitor-client privilege is claimed are segregated and packaged, which was not the case here.