About keywords

As we know keywording is a science for itself, i would like to know if "4k" or "4k UHDTV" is usefull as keyword or not. What do you think?

Even though there is a 4K filter, Pond5 said clients sometimes use 4k in a search. I think one might as well use 4K and UHD.

Thanks Videostock50, that is also my thinking!