There were two golden rules for anyone daring to put a finger or any other part of his anatomy into a ruck at the wrong time against France in the amateur era.
Rule one: Don’t do it.
Rule two: If you do decide to do it, always refer to rule one.
Unfortunately, for Wales prop John Davies he evidently hadn’t familiarised himself with such ideas.
He had some memorable encounters with the French over the course of his career.
But maybe none were as painful as the one which saw the then farmer have his finger bitten by France hooker and captain Jean-Francois Tordo.
It left such a deep impression on Davies that when he went home to his farm at Boncath in Dyfed he named his pet dog after the man who had munched him.
Happy days?
Sort of.
This weekend, the concern for Wales’ props Gareth Thomas and Tomas Francis will largely involve how to hold their own in a relatively straightforward pushing and shoving contest with their opposite numbers.
Close on three decades ago, matters were a shade more complicated.
How shall we put this?
Dark arts ruled, especially in French rugby, where front rowers were particularly vulnerable.
Not that it bothered all.
"Am I daunted about going out to Paris?" said Garin Jenkins before heading for the French capital with Wales under Graham Henry in 1999.
"Not at all. It’s a game of rugby and nothing more.
"No-one’s going to be singing The Old Rugged Cross at the final whistle. You just go there, play the match, enjoy it and go home. End of."
Call that signature Garin.
Utterly fearless at a time when not everyone shared such a trait ahead of a game with Les Bleus.
But scrapes did happen.
Ask Davies about his 1993 visit to the city of the Louvre, the Eiffel Tower and the Seine.
"I was in a maul with my hands on the ball trying to rip the ball clear when all of a sudden I felt this shooting pain," Davies said of the infamous episode in the encounter at Parc des Princes all those years ago.
"I looked down and there was their hooker with his teeth around one of my fingers. I had to pull it out of his mouth.
"There wasn’t a lot I could do. By the time I had ripped it clear, the ball had gone elsewhere and the game had moved on.
"A lot used to go on in rugby in those days, but you still didn’t expect to be bitten.
"I didn’t speak with him about it after the game. I just put the incident down to experience.
"When I got back to Wales we had a boxer pup and decided to call him Tordo.
"The whole episode was different. But Tordo was a great dog."
Tordo the rugby player? Sadly for him he played just one more Test before having his face stamped on in a tour match in South Africa. The injury was bad enough to require 50 stitches.
France wasn’t the only dangerous place to play rugby at that time.
Davies stuck around a lot longer than he did, playing until 1998 and winning 34 caps along the way.
He wasn't the only Wales player to hit problems against the French in that era.
In the book, 'Behind the Dragon: Playing Rugby for Wales', Gareth Llewellyn calls the matches the "dirtiest games you'd play in".
He continues: "Gouging your eyes was standard, part of the deal. I had a huge scar on my arm for years after being bitten by Jean-Francois Tordo. John Davies did as well. He actually named his dog after him because it used to bite him all the time."
Maybe the then French No. 2 should have eaten more at home.
Davies endured another unfortunate moment against France in his only second game for Wales, in 1991. This time it wasn’t down to skullduggery in any shape or form. It was down to inexperience on his part and immense opposition scrummaging.
The then rising star at Neath had just turned 22 but the French were not about to take pity on the youngster manning the Wales tight-head post. Early in game they switched on full power at a scrum and carnage resulted.
Davies was treated to a bird’s eye view of Paris, with the French front row popping him so high out of the scrum he would have seen all the sights without having to climb the hill that leads to the artists’ quarter and the Sacre-Couer.
"It was probably my most embarrassing moment in rugby," he said.
"They got underneath me and I wasn’t able to hold my ground. Whoosh — up I went.
"It was a mistake on my part, a bit of inexperience. They shoved before I had bound properly with our lock Glyn Llewellyn."
It could have spelled the end of a promising Test career, but Davies recovered to the point where he became one of Wales' front-row stars of 1990s.
Indeed, when Welsh top-flight coaches were asked to pick a dream team of players who had featured in the first five years of the Heineken League Premier Division, there was only one unanimous choice and that was Davies.
He had built his reputation as part of Neath’s all-farming front row with Brian Williams and Kevin Phillips, the trio travelling across to The Gnoll from west Wales to train and play.
"They were great days," Davies said.
"It came as a shock when Brian passed away so young.
"He was only 46 and that is way too young for anyone to leave us.
"It was a great experience playing and training alongside him, Kevin and the others at Neath — humbling. I went there as a raw 19-year-old, a boy really, and was educated in rugby and the ways of the world. It was a life education, something I’ve always been grateful for."
The front rower who represented Richmond and the Scarlets isn’t one for dwelling on what might have been, saying: "There are no regrets.
"I played for some great clubs in Neath, Llanelli and Richmond when they were doing well in the English Premiership. I also had a good run with Wales and had a good stint with my local club, Crymwch. You are what you are given, and it’s about doing as well as you can and trying to make the most of it. I loved playing."
Fingers crossed, no Welsh player will have a digit nibbled this weekend.
But maybe the best advice is be prepared for anything.
John Davies would doubtless agree.
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