About label classifications
Label classifications help you group your account components into meaningful sets. For example, you can create a parent label classification called “Geo,” create a different label value for each geographical region (such as “United Kingdom” and “Japan”) within the classification, and then assign the label values to your bid units or parent campaigns. You can then include any label value as a separate column in your views and reports, and subpivot your reports on different classification groups and values.
Label classifications
Each advertiser can have up to 30 label classifications, which are top-level categories.
Label values
Each label classification can have up to 2000 values. Once you create specific label values for a classification, you can assign them to campaigns, ad groups, keywords, ads, placements, and product groups from the campaign management views or using bulksheets.
Each eligible entity can have label values for multiple classifications but only one label value per classification. Label values are inherited by child entities but can be overridden. The value assigned at the lowest level always overrides values assigned at parent levels.
The Labels Classifications view
The Labels Classifications view within the Search > Campaigns menu includes Classifications and Label Values subviews. You can view data for your label classifications, create and delete label classifications, and view data for your label classification values. By default, data is shown for your keyword-level label classifications and values, but you can optionally view data for your ad-level classifications and values.