Provisional attachment protects revenue in wealth-tax proceedings by permitting temporary seizure of assets pending assessment. Section 34B voids transfers or charges on an assessee's assets made during or after proceedings but before service of the applicable notice as against revenue claims, subject to exceptions for adequate consideration without notice and transfers made with prior permission of the Wealth-tax Officer; 'assets' are defined to include specified capital items and bank fixed deposits not forming part of stock-in-trade. Section 34C authorises provisional attachment of property by the Wealth-tax Officer with the Commissioner's prior approval to protect revenue during assessment or escaped-assessment proceedings, with initial six-month duration and limited extensions upon recorded reasons.