Category Not Set

      WP_Term Object
(
    [term_id] => 15
    [name] => Category Not Set
    [slug] => category-not-set
    [term_group] => 0
    [term_taxonomy_id] => 15
    [taxonomy] => product_cat
    [description] => If the product does not have a category, it will be tagged with "Category Not Set" on Import
    [parent] => 0
    [count] => 0
    [filter] => raw
    [term_order] => 1
)
    

If the product does not have a category, it will be tagged with "Category Not Set" on Import