The chain ring mark is known in road racing circles as a “Cat 4 Tat”, on the basis that amateur racers are more likely to have dirty chains, and hang around with their chain on the inner chainring.
Why would you want to have it permanently and indelibly etched onto your calf?? It’s a faux pas, not a badge of honour! Or are people so desperate for the wider public to know that they’re a cyclist that they would tattoo a dirty mark on their leg???
It’s only a faux pas to road racers, a bit like the whole white sock thing, and the no rucksack rule. STW is an MTB website predominantly so I would think that this kind of tattoo wouldn’t be a faux pas in most peoples eyes.
Basically, your “dirty mark”/faux pas is another persons badge of honour. That’s why there are people with these tattoos out there.
Now, how about a tattoo of the pin marks that I keep getting in my shins from a set of DMR V8s? That probably would be bad form, proof that I can’t land a jump for toffee!