GST rules amendment omits specified procedural rules and redefines Authority and its functions under the Act. The amendment omits rules 122, 124, 125, 134 and 137; substitutes the marginal heading of rule 127 from 'Duties' to 'Functions' and replaces duty language with function oriented wording; and substitutes the Explanation clause to define Authority as the Authority notified under sub section (2) of section 171 of the Act.