So I accidentally wrote "DO NOT USE" on my *actual* laundry card rather than the one I'm using for shenanigans, whoops.
Sharpie comes off with IPA though, so it should be fine.
On that note I think it's time for bed.
Welcome to your niu world ! We are a cute and loving international community Ｏ(≧▽≦)Ｏ !