magento-test/app/code/Magento/Catalog/etc/catalog_attributes.xsd

<?xml version="1.0" encoding="UTF-8"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="config">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="group" type="attributeGroupType" minOccurs="1" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:complexType name="attributeGroupType">
        <xs:sequence>
            <xs:element name="attribute" type="attributeType" minOccurs="1" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attribute name="name" type="xs:string" use="required"/>
    </xs:complexType>

    <xs:complexType name="attributeType">
        <xs:attribute name="name" type="xs:string" use="required"/>
    </xs:complexType>
</xs:schema>