XML Validation

To ensure that Google can process your feed, use an XML schema validator before submitting your feed. You can use xmllint to validate your feed with this command:

xmllint --schema http://www.google.com/shopping/reviews/schema/product/2.3/product_reviews.xsd \
        --noout file.xml

Alternatives

There are a number of tools available to help you validate the structure of your XML files: