Category can be specified by Name or by existing category ID. If the category doesn't exist it will be created. Category is Required.
Tags can be specified by Name or by existing tag ID. Tag Field should be enclosed in quotes. Multiple tags should be delimited by commas. If the Tag doesn't exist, it will be created. Example: "Tag 1,Tag 2"
Note. if you are using a CSV editor such as Excel, it will inclose the tags in quotes for you, so don't add the quotes in Excel.