About custom fields configuration

What is the use for the parameter Core in the custom fields configuration?
We can see it in the last column in the screenshot of the documentation.

www.hikashop.com/support/documentation/i...p-field-listing.html

Thanks
Max.

Hello Max,
As it's said on the documentation :

Delete : Select one or several custom fields and click on this button in order to completely delete them. You can't delete core custom fields which are the custom fields there by default. You can however unpublish them. When you delete a custom field, the column in the table is removed along with all the data in it.