I mean sharpies are just "another system ontop of the dollar" but whatever. Bitcoin is a token that is not completely fungible to be specific. I am using your logic (one of subjective value applied to data outside of the necessary cryptography) to illustrate that using arbitrary (which by the way means not necessary) data reduces the fungibility of bitcoin. It is therefore easily recognizable as a non-monetary use. Because that very fugibility is what is relied on to function as money. As far as being an NFT, re-reading my comment I did miss a word and I apologize, It was supposed to read: "Then bitcoin is not fungible. It is literally a non-fungible token" I meant to take on your perspective that it holds some kind of subjective value outside of money. That's where shit got kinda off the rails. I don't think that Bitcoin is completely fungible (because of arbitrary data, signature chains and other identifying data) but from what I perceive to be your perspective, it should be less fungible.