It's spelled Chinook, from The Chinook people of Native Americans.
^The spelling of chinook in the description is what you took from this? well done.
@Anonymous Thanks, you made my day
I think this is boloney. Out of all the sign language the handler shows to the dog, the dog probably "understands" only one hand movement at the end, and when I say "understand" I mean only that the dog associates a specific hand movement with a specific task. That's it. Dogs do not have complex language skills.