It is Slovenia, as others have guessed. It's just one way people find to express their predjudice, I'm sure others exist in any other part of the world. My last name ends with a C and it sometimes gets written with a Ć and I don't lose my mind because I'm not a bigot. Also, I'm happy to see more and more people standing up for their identity - as in, please put Ć on the form because that's how it's properly spelled; yes, my ancestors come from the south and no, I don't care what you think about that, just do your job properly!
It is remarkable that this exact border (although without the proverbs on Ć) manifests also between Czech Republic and Poland -- in the Czech language there is exactly one hard "Č" and no soft version, whereas Polish has both "cz" (the hard variant) and "Ć" (the soft variant).
