Blueprints

// site/blueprints/pages/blueprint.php
$fields = [...]; // Fields for all users

if (kirby()->user()->isAdmin()) {
    $fields = [...] // Fields for admins
}

return [
    'title' => 'PHP-based blueprint',
    'fields' => $fields,
];

blueprints
  ├── pages
  │   ├── default.yml
  │   ├── home.policy.yml
  │   ├── simple.policy.yml
  │   ├── content.yml
  │   └── post.policy.yml
  ├── users
  │   ├── admin.yml
  │   └── editor.yml
  └── site.yml

return Field::make(FieldTypes::TEXT)
    ->label('Description')
    ->toArray();