| 4 | | Just to clarify, is it about the instance in `wp-includes/feed-rss2.php` or `wp-admin/includes/export.php`? Is there an actual problem solved by removing this line? As explained in comment:1, a namespace URL does not need to resolve. It may look like a URL, but it is just a unique identifier of the namespace. |
| | 4 | Just to clarify, is it about the instance in `wp-includes/feed-rss2.php` or `wp-admin/includes/export.php`? Removing the former would result in invalid XML, as it's used for `wfw:commentRss`. |
| | 5 | |
| | 6 | Is there an actual problem solved by removing this line? As explained in comment:1, a namespace URL does not need to resolve. It may look like a URL, but it is just a unique identifier of the namespace. |