Hi,

There are several fields that are essential for the feed to function properly:

ID (external_id): unique and not changeable within one XML character varying (up to 32 characters - no Polish letters)

Name: up to 100 characters
Brand: up to 512 characters
Main category (category_main): up to 200 characters
Description: up to 1024 characters
Price: number, decimal values up to two places after the dot
Product URL (url_product): up to 512 characters
Image URL (url_img): up to 512 characters