CDN may mean 'Canadian'. I've seen UK VMT on some of my uploads.
VMT is something like a 'holding space' for new keywords, particularly, but apparently not restricted to, brand names.
Someone may be able to tell us what VMT stands for.
Oh, via iStock's forum search, I found that Ducksandwich, from Team Metadata, posted:
"Vocabulary Management Team is not a CV term nor a reference to any team. These are some terms we are working with and you can expect to see more of them in the future"
