# Property names

> Customize variable names for object properties using the `x-fern-property-name` extension

The `x-fern-property-name` extension allows you to customize the variable name for object
properties.

For example, if you had a property called `_metadata` in your schema but you wanted the
variable to be called `data` in your SDK you would do the following:

```yaml {6}
components:
  schemas:
    MyUser:
      _metadata:
        type: object
        x-fern-property-name: data
```