I wish we would have a box for production companies in the "Production Information" page, just like "Production Countries" and "Network".
Some of the famous k-drama production companies:
Information about them can be easily found on Wikipedia.
I was about to make this suggestion too ;)
I think it would be great to add only one producer too, even if she/he's not part of a production company, for example as an another job in the crew section, like the writers and directors.
I don't know if I should make another thread for that but since it also concerns production, I'll just leave it here.