Must cufflinks be worn with a french cuff shirt? Are they the only thing that is acceptable to hold the cuff together?

Is it appropriate at all to wear the rubbery ball things that sometimes come with shirt? Would you judge someone poorly for wearing a french cuff shirt in an informal situation? Could this informal situation be the perfect time to wear the rubbery things to not look snooty or would this just be a big fashion faux pas in any content?