According to an Italian friend calzino/calzini is used for sock/socks, and the plural of calza = calze is used when talking about stockings these days. Parts of the internet seem to agree that calza for sock sounds a little bit outdated. Any other thoughts/opinions on that? (That makes for a disturbing image with everyone here talking about Dobby in calze...)
Edit: Okay, people already remarked that, but apparently this course doesn't teach you calzino/calzini in the cloths section. Maybe it would be good to change "calza/calze" to "calzino/calzini" for socks here. (Apparently the duolingo-team made "stocking" already the standard translation for "calza" - but I think teaching the words for sock/socks would be more useful)
This makes sense if you translate it more as "covering." In Italian it is a foot covering. A stocking goes over the knee, so a "little stocking" would not go past the knee (and would be a sock). In Portuguese it is a covering of the lower body, so a "little cover" would go only a little way down (panties). Meias cover your feet. So stockings (which can be considered nylon pantyhose) would need to cover your butt and your feet (calças-meias).