## Setting Up Custom Data Shipping Properties

To add custom properties to data shipping logs, append the query parameter `property` on the event URL with a key/value pair in the format `property:key=value`:

### Custom data shipping property query parameters

```text
https://e-{networkId}.adzerk.net/e.gif?e=eyJ2I...tHmz3q0&property:foo1=bar1&property:foo2=bar2
```

Note that multiple properties can be appended. They are limited by the max length of the URL.

When the event URL is called, properties will then appear in data shipping logs:

### Custom data shipping properties in logs

```json
{
  "Meta:schema": "event",
  "Meta:version": "1.2",
  "Properties": {
    "foo1": "bar1",
    "foo2": "bar2"
  },
  ...
}
```

| Log Type                          | Where to Append Properties                                                  |
|------------------------------------|---------------------------------------------------------------------------|
| Request                            | The Decision API URL                                                     |
| Decision                           | `placement.properties` in the Decision API request (note that these can also be used for custom targeting) |
| Selection                          | N/A                                                                     |
| Impression                         | Impression URL (includes static text links but not email ad code)      |
| Click                              | Click URL (includes static text links and email ad code)                |
| Conversion/Custom Event            | Conversion/event URL                                                    |
| UserDB                             | UserDB API endpoints                                                    |