Custom labels
Also known as: Custom label 0–4
In short
Merchant-defined product attributes used to group items by business criteria for advertising reporting and campaign organization.
Turn business rules into product groups
Custom labels attach your own classifications to product records. Useful dimensions might include season, margin band or merchandising priority. The label describes the group; the campaign configuration decides how that group is used.
Google Merchant Center provides five fields, custom_label_0 through custom_label_4. Each field accepts one value per product. These values are intended for internal reporting and advertising organization, rather than customer-facing product information.
Define a purpose for each field so the same value means the same thing across the catalog. Mixing a season and a margin band in one field makes filtering harder to interpret.
Illustrative example
Imagine a retailer assigning custom_label_0 to a stock classification. A verified inventory rule assigns well-stocked or limited-stock. A separate field holds the merchandising season.
The advertising team can then select a seasonal assortment with adequate stock. The label itself does not reserve inventory, change a bid or exclude a product automatically.
Keep the rules maintainable
Use a controlled set of values and update labels when the underlying facts change. Google limits the number of unique values per field, so creating a different label for every product defeats the grouping purpose. Check processed values and campaign filters together before relying on a segment.