Пример прайс листа в формате XML

sku - уникальный код товара
обязательные: 
name 
price


<offers> 
    <categories>
        <category id="801">Напитки</category>
        <category id="802">Мясо и колбасы</category>
        <category id="803" parent="801">Соки</category>
        <category id="804">Молочные продукты</category>
    </categories>

    <offer sku="123qweqwe34"> 
        <name>Колбаса вареная "Любимов"</name> 
        <price>400.00</price> 
        <measure>кг</measure> 
        <brand>Дымов</brand> 
        <store_id>1034</store_id> 
        <start_date>2014-10-20</start_date>
        <finish_date>2014-10-26</finish_date>
        <categoryId>802</categoryId>
    </offer>
    <offer sku="123qweqwe"> 
        <name>Колбаса сыро-копченая "Дымов"</name> 
        <price>740.00</price> 
        <measure>кг</measure> 
        <brand>Дымов</brand> 
        <store_id>1043</store_id>
        <start_date>2014-10-20</start_date>
        <finish_date>2014-10-26</finish_date>
        <categoryId>802</categoryId>
    </offer> 
</offers>

Схема валидации XML:

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
	<xs:element name="offers">
		<xs:complexType>
			<xs:sequence>
            	<xs:element name="categories" minOccurs="0" maxOccurs="1">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element ref="category" minOccurs="0" maxOccurs="unbounded"/>
                        </xs:sequence>
                    </xs:complexType>
                </xs:element>
				<xs:element ref="offer" minOccurs="1" maxOccurs="unbounded"/>
			</xs:sequence>
		</xs:complexType>
	</xs:element>
	<xs:element name="offer">
		<xs:complexType>
			<xs:sequence>
				<xs:element name="name" type="xs:string" minOccurs="1" maxOccurs="1"/>
				<xs:element name="price" type="xs:decimal" minOccurs="1" maxOccurs="1"/>
			        <xs:element name="measure" type="xs:string" minOccurs="0" maxOccurs="1"/>
				<xs:element name="description" type="xs:string" minOccurs="0" maxOccurs="1"/>
				<xs:element name="store_id" type="xs:integer" minOccurs="0" maxOccurs="1"/>
				<xs:element name="storesgroup_id" type="xs:integer" minOccurs="0" maxOccurs="1"/>
				<xs:element name="brand" type="xs:string" minOccurs="0" maxOccurs="1"/>
				<xs:element name="barcode" type="xs:integer" minOccurs="0" maxOccurs="1"/>
				<xs:element name="start_date" type="xs:date" minOccurs="0" maxOccurs="1"/>
				<xs:element name="finish_date" type="xs:date" minOccurs="0" maxOccurs="1"/>
				<xs:element name="categoryId" type="xs:integer" minOccurs="0" maxOccurs="1"/>
				<xs:element name="picture_url" type="xs:anyURI" minOccurs="0" maxOccurs="1"/>
			</xs:sequence>
			<xs:attribute name="sku" type="xs:string" use="required"/>	
                </xs:complexType>
	</xs:element>

	<xs:element name="category">
		<xs:complexType>
			<xs:simpleContent>
				<xs:extension base="xs:string">
					<xs:attribute name="id" type="xs:integer" use="required"/>
					<xs:attribute name="parent" type="xs:integer" use="optional"/>
				</xs:extension>
			</xs:simpleContent>
		</xs:complexType>
	</xs:element>
</xs:schema>