Audit principles for Central Excise and Service Tax establish uniform procedures and supervisory guidance for auditors. The manual prescribes principles and policies for conducting audits under the Central Excise Act and the Finance Act for Service Tax, focusing on uniform, efficient and comprehensive audit conduct rather than legal interpretation. It confines its scope to audit-related principles and special issues, excludes legal rulings, directs auditors to seek supervisory guidance when issues fall outside the manual, and provides for periodic amendments and temporary instructions to remove implementation difficulties.