Former Super League official Karl Kirkpatrick has become the first referee to switch codes and join union.
Kirkpatrick took charge of the 2006 Super League Grand Final
The 42-year-old quit rugby league after he was left off the Super League list following his decision to keep his banking job rather than go full-time.
"It's something that's never been done before and it's got my adrenalin going," he told BBC Radio Lancashire.
"Just like Jason Robinson, Andy Farrell and coaches crossing over, it's a question of taking a structured path."
Kirkpatrick, who has 14 years' experience at the top level, has been restricted to National League team games this year after refusing to accept the Rugby Football League's offer to go full-time.
And he was the notable omission when the League unveiled their panel of six full-time referees earlier this year.
He was sounded out by the Rugby Football Union before he took charge of the 2006 Grand Final and has begun work on the 15-a-side game at the West Park club in St Helens.
Kirkpatrick, who also controlled the 2004 Challenge Cup final, is being advised by former Great Britain forward Denis Betts, who is now on the coaching staff at Gloucester.
"Karl has enjoyed a very successful career as a grade-one match official and we would like to take this opportunity to thank him as well as wishing him all the very best for the future," said RFL match officials director Stuart Cummings.