AI-generated Key Takeaways
- 
          Custom fields are user-created fields that can be added to entities in the system. 
- 
          Custom fields have attributes such as ID, name, description, active status, associated entity type, data type, and UI visibility. 
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          The CustomFieldServiceallows for the creation and updating of custom fields.
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          Custom fields can be associated with different entity types, including Line Item, Order, Creative, Proposal, and Proposal Line Item. 
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          Custom fields can store various data types, such as string, number, boolean (toggle), or values from a drop-down list. 
An additional, user-created field on an entity.
- Namespace
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               https://www.google.com/apis/ads/publisher/v202505
| Field | |
|---|---|
| 
                            | 
                            Unique ID of the  | 
| 
                            | 
                            Name of the  | 
| 
                            | 
                            A description of the custom field. This value is optional. The maximum length is 511 characters | 
| 
                            | 
                            Specifies whether or not the custom fields is active. This attribute is read-only. | 
| 
                            | The type of entity that this custom field is associated with. This attribute is read-only if there exists a CustomFieldValue for this field. Enumerations 
 | 
| 
                            | The type of data this custom field contains. This attribute is read-only if there exists a CustomFieldValue for this field. Enumerations 
 | 
| 
                            | How visible/accessible this field is in the UI. Enumerations 
 |