An atomic rule item.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v25/common/user_lists.proto)

| Fields ||
|---|---|
| ## `name` | `string` Rule variable name. It should match the corresponding key name fired by the pixel. A name must begin with US-ascii letters or underscore or UTF8 code that is greater than 127 and consist of US-ascii letters or digits or underscore or UTF8 code that is greater than 127. For websites, there are two built-in variable URL (name = 'url__') and referrer URL (name = 'ref_url__'). This field must be populated when creating a new rule item. |
| ## `rule_item` Union field. An atomic rule item. `rule_item` can be only one of the following: ||
| ### `date_rule_item` | `https://developers.google.com/google-ads/api/reference/rpc/v25/UserListDateRuleItemInfo` An atomic rule item composed of a date operation. |
| ### `number_rule_item` | `https://developers.google.com/google-ads/api/reference/rpc/v25/UserListNumberRuleItemInfo` An atomic rule item composed of a number operation. |
| ### `string_rule_item` | `https://developers.google.com/google-ads/api/reference/rpc/v25/UserListStringRuleItemInfo` An atomic rule item composed of a string operation. |