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The "con.txt" example is also interesting because, unlike the invalid characters, it is still a valid FAT/ExFAT/NTFS filename so you can create a file on, say, your flash drive with another system with a device name as its filename (irrespective of extension) and then not be able to interact with it on Windows! (There is a workaround with UNC paths which I've used in the past to troll friends/family/coworkers/etc with files on their HDD they can't delete…)
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