Thanks Nicolas,
So if I understand correctly, the parent_category can be anywhere in the category tree structure and the category column reflects sub-categories of that particular parent_category only. Is that correct?
Rather than put all sub-categories in a single column on one row in the spreadsheet, for the sake of readability could each sub-category be on its own row and reference the same parent_category? In this case I guess "Create Automatically Missing Categories" would need to be enabled.
And finally, after an import is done to create the parent and sub-categories, any product imports would include the single column "categories" which would contain all pertinent category id numbers without reference to parent/sub-category level. Correct, or am I still confused?
Regards,
Ed