What do you mean by this?
> It’s a shibboleth
It is known by all. What definition are you using for "shibboleth"?
> It’s referred to when there’s a need to call on a talisman...
There's not a need to refer to the rules in any game unless one participant thinks that the rules have been broken.
And as for shibboleth:
> The term can also be used pejoratively, suggesting that the original meaning of a symbol has in effect been lost and that the symbol now serves merely to identify allegiance, being described as "nothing more than a shibboleth". In 1956, Nobel Prize-laureate economist Paul Samuelson applied the term "shibboleth" in works including Foundations of Economic Analysis to an idea for which "the means becomes the end, and the letter of the law takes precedence over the spirit."[14] Samuelson admitted that "shibboleth" is an imperfect term for this phenomenon.[15]
* different enough that it matters to people who care about modern day politics