Polylang offers the possibilty to synchronize some meta content and options between translations of posts or pages. These are:
- Categories and post tags (as well as other custom taxonomies) when they are translated
- Custom fields
- Comment and ping status
- Sicky posts and published date
- Post format
- Page hierarchy, page template, and page order
- Featured image
Although this feature will appears nice to some users, not everyone will be happy with it. Thus the synchronization is de-activated by default and you can activate it by unchecking the corresponding option in the Synchronization section of the languages settings.
Note: Plugins and themes authors may choose to overwrite the user choice and force some of these synchronization programmatically, or by the mean of a wpml-config.xml file for custom fields.