A dictionary is a resource that lists the words of a language and gives their meaning (typically). I wouldn't pair this with "copyright". People are fairly familiar with what a copyright is, and those looking up copyrights can do so by calling up specific, established organisations that take care of that kind of thing. I think instead of the word "dictionary", a word like "list" or "search" would be more appropriate, presenting what company has what copyright...and all the typical detail with that. But again, existing sources are out there (and relied on)
I struggle. Low value, in my view (sorry)