Provisional attachment of property permitted after service of show cause notice, subject to officer opinion and prior commissioner approval. Provisional attachment allows Central Excise officers to attach property of a person served with a show cause notice during the pendency of related proceedings; such attachment requires the officer's opinion that it is needed in the interest of revenue and prior approval of the Principal Commissioner or Commissioner. The procedure is governed by the Service Tax (Provisional Attachment) Rules, 2008, with an initial six month period and written extensions by the Chief Commissioner subject to a capped total duration.