I don't think they are out yet in the US, only available for preorder at either Entertainment Earth or Big Bag Toystore or something.
People just made unofficial names/numbers for the sets so people could easily tell which set they were talking about. The blind bag sets were named in order of each being sold anywhere in the world.
So I think we are up to this now:
Wave 1 - Pink bags, available in Europe then the US
Wave 2 - Purple bordered bags, available in Europe only (skipped the US)
Wave 3 - Purple suitcase bags, available in Europe, then the US
Wave 4 - Blue Bags, available in Europe, then the US
Wave 5 - Yellow bags (2 different styles), available in Europe now, coming to the US soon
Wave 6 - Dark blue/purple night sky bags, available soon in the US, but no signs of a European release