Proviso substitution aligning IGST notification with Section 22 explanation, altering territorial reference and effective from February. The notification amends the proviso to Notification No. 10/2017 by substituting the prior constitutional cross-reference with the first proviso to sub-section (1) of section 22 read with clause (iii) of the Explanation to section 22, aligning territorial applicability with the Explanation to section 22; the amendment is issued under powers in the IGST Act read with the CGST Act and is effective from the first day of February, 2019.