I am driving to Canada and was told by an outfitter to have this CBP form 4457 filled out.

I have been driving to Canada since the mid 1970's, and never filled out this form.
I believe this form says you are taking items with you so when you come back this form proves you own the item and did not purchase these items
abroad? Is this for flying only?
The form sure does not give much room for writing down items, such as gun serial #'s, binocular serial #'s ect.
Never heard of this form before. I fill out forms going into Canada with firearms.
I am driving not flying.
Thanks Brian