Safe Steps to Proceed
1. Audit Usage: Search your codebase, macros, and SQL for pl-EN and Check page aliases, redirects, and culture-specific settings.
2. Backup First: Export your site or at least the affected culture content before making changes.
3. Update Culture Code: In Localization → Cultures, change the code from pl-EN to en-PL.
4. Fix URLs and Redirects: Set up 301 redirects from old URLs to new ones to preserve SEO and user experience.
5. Test Thoroughly: Validate page routing, localization, and content availability across the site.
6. Update SQL Logic: If you're using custom export/import logic or recursive joins, make sure your queries normalize culture codes consistently.