I met it as the Hoss Tack. A crazy jibey looking thing in Aruba, as performed by Andy Brandt and Jason Voss. A carved question mark. That was 2000.
I was hitting the occasional Hoss (ugly but dry) a few months later, but not long after that I caught the move on a Peter Hart tape, which referred to the move as a Push Tack. Boar-ring! Who wants to do a push tack? Where is the poetry? Hoss tack please! But by and by I kept hearing and reading "push tack" and finally found self saying "'hoss tack', usually called 'push tack'" to cover my ass. There was no joy in Puffinville.
Then just a few days ago I stumbled over this: "The Haas-Tack is a flashy transition that integrates a variety of technical skills such as switch stance riding, backwinding, and clew first sailing. When mastered this move is a flowing and artistic maneuver showing graceful sail and board control. Sometimes called (erroneously) a Push-Tack. Invented by Hass Jahrmarkt of Tangier, Morocco while experimenting with a variation of the Duck-Tack." You can also find it spelled "Hass"...I suppose only Mr. Jahrmarkt knows for sure.
Did some Googling and found this in several places. Erroneously called a Push-Tack! They might have added "unimaginatively" and "boringly" and "tediously"! Yeah! Haas! Go throw a Haas Tack. If you can't, go learn it. (I know the idea of backwinded clew-first sailing in planing conditions does not immediately sound...attractive or attainable, it is possible and it is fun. I hit my first one on a Seatrend slalom board with a cammed 7.5 sail. That is about as stupid as it gets, and I suck at freestyle, and I still hit it. So you definitely can!)
(In the video at the top, I hit (barely) a Haas Tack in Bonaire while being coached by Pete Dekay in an ABK clinic (2004). The still photo is of Hoss, for whom I thought the tack was named. Now I'm wondering if the dude tacks at all.)