A Search Theme criterion only on Performance Max campaign. Represents a keyword-like advertiser input.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/common/criteria.proto)

| Fields ||
|---|---|
| ## `text` | `string` Each Search Theme has a value of a simple string, like keywords. There are limits on overall length, allowed characters, and number of words. |