My DD recently bought a set of curtains from Dunelm. When she got them home and opened them up, she noticed that the curtains didn't have any rings (eyelets) in them allowing them to be hung up on a pole. She subsequently decided to return them to the store on the basis that they aren't fit for the purpose they were purchased for - to be hung up on a pole, like every other set of curtains I have seen in my several decades of life. There was no way to know that these were ringless curtains based on the packaging. She said she just assumed they would have the rings, as every other set of curtains she has seen in people's houses (or owned herself) has had them. There was also no gap in the top of the curtains to allow a pole to slide through them.
The thought has since occurred to me - how are you supposed to hang them up if they don't have rings or a gap in for the pole to go through? Do you stick them on to the pole with velcro? Clothes pegs? Superglue? None of those suggestions seems appealing to me, and the pegs in particular would look ridiculous I imagine.