Facebook ads - Products feed - Multiple shipping zones setting - facebook-feed

Question

I'm writing a feed from an e-shop, to give to facebook.
So far so good. The feed is in XML format, and the reference provides a sample, and the format for the shipping field in the item, within the feed, is:
<g:shipping>
<g:country>UK</g:country>
<g:service>Standard</g:service>
<g:price>4.95 GBP</g:price>
</g:shipping>
However, the reference states that the format should be a comma-separated string, like this:
Blob with different prices for each country and region.
Different regions are comma-separated.
The format should be COUNTRY:STATE:SHIPPING_TYPE:PRICE.
e.g.
US:CA:Ground:9.99 USD, US:NY:Air:15.99 USD
Do you catch the contradiction?
If I try in my feed:
<g:shipping>US:CA:Ground:9.99 USD, US:NY:Air:15.99 USD</g:shipping>
I get errors, that country or price is missing.
So, I will have to stick to the sample.
The question is:
Which is the right way to provide multiple shipping zones in the feed?
The debugging tool here is not helping at all...
Do I repeat the g:shipping fieldset?
<g:shipping>
<g:country>UK</g:country>
<g:service>Standard</g:service>
<g:price>4.95 GBP</g:price>
</g:shipping>
<g:shipping>
<g:country>US</g:country>
<g:service>Standard</g:service>
<g:price>5.30 GBP</g:price>
</g:shipping>
Do I iterate within the fieldset?
<g:shipping>
<g:country>UK</g:country>
<g:service>Standard</g:service>
<g:price>4.95 GBP</g:price>
<g:country>US</g:country>
<g:service>Standard</g:service>
<g:price>5.30 GBP</g:price>
</g:shipping>
Or what, if anything, do I have to do to have multiple zones, before switching to CSV (which I don't want to do, but I will if I have to: CSV supports the comma-separated format for multiple zones)?

Answer 1

I'm answering this here for future reference.
The template used by Facebook is the one provided by Google Merchant Center.
As stated here
Include the optional sub-attributes if you need them.
To specify a shipping cost for different delivery locations,
submit multiple shipping attributes including the relevant sub-attributes.
<g:shipping>
<g:country>US</g:country>
<g:region>MA</g:region>
<g:service>Ground</g:service>
<g:price>6.49 USD</g:price>
</g:shipping>
<g:shipping>
<g:country>US</g:country>
<g:region>MA</g:region>
<g:service>Express</g:service>
<g:price>15.99 USD</g:price>
</g:shipping>

Answer 2

For anyone gets warnings about shipping_price_value, shipping_price;
If you are using php and SimpleXMLElement add xmlns:g: to define xml namespace otherwise facebook throws warnings.
Interestingly this only affects shipping fields.
$shipping = $item->addChild('xmlns:g:shipping');
$shipping->addChild('xmlns:g:country', 'TR');
$shipping->addChild('xmlns:g:service', 'Karayolu');
$shipping->addChild('xmlns:g:price', '14.90 TRY');