Under Air Force naming conventions, Y designates prototype, F means fighter, and Q means unmanned. Once a prototype moves into production, the Air Force would drop the Y from the prefix.
The chief said the unveiling represented far more than a name.
“We have two prototypes of Collaborative Combat Aircraft that were on paper less than a couple of years ago,” Allvin said. “For the first time in our history, we have a fighter designation in the YFQ-42 Alpha and the YFQ-44 Alpha—maybe just symbolic, but it’s telling the world that we are leaning into a new chapter of aerial warfare.”
https://www.airandspaceforces.com/americas-first-unmanned-fighters-yfq-42-yfq-44/