Hello OCATS!
I'm trying to get in touch with other libraries that are collecting 4k Ultra HD Blu-ray movies. We've got a growing collection at University of Toronto but it's difficult for users to find them because there is no way to facet for them - the term primarily appears in transcribed or cataloguer-created fields, and the term varies (UHD, Ultra HD, Ultra Hi Def, Bluray vs Blu-ray, etc). I'm working with Yoko Kudo, the OLAC MAC representative, to put forward a proposal to change the MARC coding for the 007/4 to include this format. But we'd like to hear from other libraries who collect this format, especially public libraries, about the size of your 4K UHD collection and if this coding would be helpful for you.
Thanks,
Kyla