GST classification: Synthetic and artificial staple fibres designated under Schedule 3 and subject to scheduled taxation measures. Synthetic and artificial staple fibres, under tariff headings 5503, 5504, 5506 and 5507, are classified as goods attracting Schedule 3 GST treatment at the prescribed rate for the specified limited period, making supplies or imports of these fibres subject to Schedule 3 taxation and related compliance obligations.