In some instances you may have categories in your own store, that you don't require mapping to Trade Me categories (e.g. promotional or sale categories such as "15% off selected winter items").
On the page where you map by category, you can "Ignore" a store category and remove it from the list of categories to be mapped.
e.g.
Note: You can always find and view these categories by using the search filter labelled "Filter by ignored" (see above).