Navigate to Feed Rules in the feed tool. To begin, select Identifier Exists as your attribute to Modify:
Click Add Rule
Fixed Attribute Value
Set to False
Next - Build your filter (See below)
NOTE: Generally speaking, if you did not include GTINs for products in your store then you can apply a filter for the following (continue reading for general filter building guidance):
Field > GTIN Type > Is Empty (No value needed)
Build filters to ensure your modifications are only applied to products that match your criteria. By not creating a filter, you are enabling a rule to apply to ALL PRODUCTS in your feed. Filters can consist of single attribute criteria or multi-attribute criteria by clicking Add Filter to build each additional criteria desired.
AND vs OR Filters
Filters can differ by their function using AND / OR logic. To create an OR logic, a filter must have multiple values entered at once:
To create AND logic, there must be multiple filters that all determine the select criteria:
Nullifying Brand & MPN
Repeat the steps above, adding rules for both Brand & MPN and setting the Text Attribute Builder to [Null]:
Set the same Filters from your Identifier Exists Rule, click Save once complete.
You can now send your feed to update it in Merchant Center.