From the upcoming 1.19 patch notes:
•[dev1161] The quality of items obtainable through gathering has been changed to NQ and HQ (+3).
Many were thinking that in the conversion of NQ/+1/+2/+3 --> NQ HQ that current NQ/+1 = NQ, and +2/+3 = HQ. Is this SE saying that, in fact, NQ/+1/+2 = NQ, and only +3 = HQ?