Service tax exemption for DDUGKY training providers prevents retrospective payment obligation for specified past period. The Central Government directed that the service tax payable under section 66B of the Finance Act, 1994, on services provided by training providers (project implementation agencies) under the Deen Dayal Upadhyaya Grameen Kaushalya Yojana-offering skill or vocational training courses certified by the National Council for Vocational Training-shall not be required to be paid for the period commencing 1 July 2012 and ending 31 March 2016, based on a generally prevalent practice of non-levy during that period.