It is possible to map the names properties going in and out of your data objects using: MapOutputName , MapInputName and MapName attributes. But sometimes it can be quite hard to follow where which name can be used. Let's go through some case:

In the data object:

class UserData extends Data
     public function __construct(
         #[MapName('favorite_song')] // name mapping
         public Lazy|SongData $song,
         #[RequiredWith('song')] // In validation rules, use the original name
         public string $title,
     public static function allowedRequestExcept(): ?array
         return [
             'song', // Use the original name when defining includes, excludes, excepts and only
     public function rules(ValidContext $context): array {
        return  [
            'song' => 'required', // Use the original name when defining validation rules
    // ...
When creating a data object:
UserData::from([
    'favorite_song' => ..., // You can use the mapped or original name here
    'title' => 'some title'
When adding an include, exclude, except or only:
 UserData::from(User::first())->except('song'); // Always use the original name here
Within a request query, you can use the mapped or original name:
https://spatie.be/my-account?except[]=favorite_song 
When validating a data object or getting rules for a data object, always use the original name:
$data = [
    'favorite_song' => 123,
    'title' => 'some title',
UserData::validate($data)
UserData::getValidationRules($data)