like so right said-the knees must be covered by a skirt regardless of the tights/socks/knee highs.
But, I have another issue with tznius. Is there any heter to wear sheer tights? Why are ppl wearing sheer stockings if the foot also hasta be covered. Why is this considered less assur than short skirts? Maybe I’m just missing the heter. You might as well go without stockings! (I’m not at the madreiga to give it up-I still wear them)