I like using religion as an example for cultural systems because they can a) be constructed (not yours of course, but all the others), and b) anyone can join (sometimes whether they like it or not). Now remember the definition of A Cultural System (1) a system of symbols which acts to (2) establish powerful, pervasive, and long-lasting moods and motivations in men.
Let's consider the Christian cross. Certainly that's a symbol that has established powerful, and pervasive moods and motivations. The theological question is whether that power comes a priori or not.
Now let's consider the use of the cross in vampire lore. Bram Stoker's Dracula recoiled from the symbol, and in doing so _gave the symbol power a posteriori_. Writing in the late nineteenth century, it's understandable that Stoker would want to reinforce Christian righteousnous, but is that the message of the symbol when wielded by Keanu and Wynona? Or Buffy and Willow?
And then what if Buffy decided to make some coin by selling crosses?
When you want everyone to know you love Jesus, and high school monster of the week shows.
The cross has value in the Buffy-verse because of its a posteriori demonstrable power against the antagonists of that world, but the symbol is also valuable because of the a priori power its supposed to have by the religious cultural group. This enables trade, and trade enables groups to get along. Crosses are pretty abundant, but if they weren't you'd be seeing christians and vampire fans at the market, and that's why trade works.
When Geertz was writing about cultural systems in the seventies, there weren't a lot of great examples of a posteriori symbols. Flags are one that comes to mind--certainly the union jack, jolly roger, and hammer and sickle are evocative and powerful symbols given meaning by the actions of their bearers. But with computers a whole new window of opportunity has opened.
Given enough time and resources, we can grant to pretty much any symbol whatever a posteriori power we want. Perhaps that fits into some lore like the vampires above, or perhaps that's part of some community like the bandcamp pass that gives me access to indie recordings I had back in the nineties.
Then by using Half-Fungibility we don't even need the same symbols visually. They can be hidden away from view and traded behind the scenes if so desired. The only limit is Our Imagination.