I've got a 50th anniversary (73-74) replica Bobby Orr, a Terry O'Reilly, a Fleet Center era blank (thinking of getting it patched as a Sandy Moger

) and a because years ago i told myself I'd get the jersey of whoever scored the cup winning goal, a road Bergy with the cup patch, which is awesome as he's my favorite current human.
My next will probably be a Lucic alternate but i'd love a Boychuk or McQuaid too...
why does this have a GDT prefix?