IT maybe doesn't happen quite as much as it used to, but there is still a special induction routine reserved for new players entering the hallowed portals of the home dressing-room at Celtic Park.
They will hear from a team-mate how the little fellow with the grey hair who takes care of the kit was actually one of the finest players in the club's history and a member of the first British team to win the European Cup.
A few people will no doubt be quietly consulted over whether this is some kind of wind-up. Unconvinced, there will be no other course of action to take than to approach John Clark and just ask him, straight out, to spill the beans.
The 73-year-old, of course, is far too modest to open his mouth and let his belly rumble about his achievements. He's usually too busy pushing hampers around or clearing up some mess or other, in any case, but there is a suitably subtle way in which he continues to answer all questions and gives new recruits an early indication of the shadow of history now looming over them.
"I don't go about telling them who I am, but I think the players spread the word," said Clark. "They will then come up and ask if it's true. If they do, you just show them the photograph down the stairs.
"I'll say to them: 'There's been big changes since then, but take a look at that. The thing in the middle with the big handles is the thing you'll always want to win.' I won it.
"It's been great. Henrik Larsson and others were great guys and, before that, you had Alan Stubbs and so on, who were all terrific to have about. Players today don't bother too much about what we did. They're more concerned with their own football now and maybe have more to think about. They count their cash while we just looked at the wage slip, but we were well looked after as players at Celtic."
Clark and the other remaining members of the Lisbon Lions, that collection of giants who humbled the seemingly-impregnable Internazionale back in 1967 and carved their names into the Celtic consciousness for eternity, will enjoy a profile this weekend, though, that the vast majority of players could only dream about.
The club have arranged to take them and the families of Jock Stein, Sean Fallon and the players no longer with us back to the Portuguese capital for Saturday evening's Champions League final between Real Madrid and Atletico Madrid. They will revisit the Estadio Nacional and be guests of honour at a special dinner in the Palacio Hotel in the coastal town of Estoril, where they stayed 47 years ago.
While Madrid is the epicentre of European football just now, Glasgow was the place to be in the late 1960s. Rangers, of course, competed in the final of the European Cup-Winners' Cup in '67, losing out to Bayern Munich in Nuremburg.
"I can't see it [a Scottish team winning club football's top prize] happening again," said Clark. "With the likes of Barcelona, Real Madrid, Bayern and PSG, the cash they all have is amazing. The way finance is in Scottish football, we're up against it. The last 16 is an achievement. It's all changed. An achievement to Arsene Wenger at Arsenal is the top four in the English League. In any other era, that sort of talk from an Arsenal manager would not have been tolerated."
As it is, the current Celtic manager, Neil Lennon, has done well to take his players into the group stage of the Champions League over the past couple of seasons.
While some of those recruited to wear the green-and-white hoops may no longer show such interest in the glories of those men who stormed Lisbon and proved the great Helenio Herrera's Catenaccio system really wasn't all that, the same cannot be said of Lennon.
He grew up following the club, he knows about the place the Lisbon Lions enjoy in the hearts of its supporters and adores spending time in their company.
Clark believes having a figurehead with such knowledge of - and respect for - the past is of significant value. "You have a feeling for the club and it must be of benefit to Neil that he knows how the fans respond," said Clark. "He wants to get better all the time and be at the forefront of everything. That's a good thing. I think you should remind people of the history of the club."
Lennon, of course, has only just joined Stein, Willie Maley and Gordon Strachan in becoming the fourth Celtic manager to win three consecutive league titles.
Still a relative rookie in the dug-out compared to those men, surely Clark can offer a fascinating insight into the progress the former player has been making since taking over the hot-seat from Tony Mowbray in March 2010.
"Aye, he's good and bad, isn't he?" responds Clark. "I won't tell you the bad things, though. I'll keep them to myself."