1<?xml version="1.0"?>
2<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
3	
4	<xsd:simpleType name="myDecimal">
5		<xsd:restriction base="xsd:decimal">			
6			<xsd:totalDigits value="18"/>			
7		</xsd:restriction>
8	</xsd:simpleType>
9
10	<xsd:element name="foo">
11		<xsd:complexType>
12			<xsd:sequence>
13				<xsd:element name="val" type="myDecimal" maxOccurs="unbounded"/>
14				<xsd:element name="ref" type="myDecimal" minOccurs="0"/>
15			</xsd:sequence>
16		</xsd:complexType>
17
18		<!--xsd:key name="myKey">
19			<xsd:selector xpath="val"/>
20			<xsd:field xpath="."/>
21		</xsd:key>
22
23		<xsd:keyref name="myKeyRef" refer="myKey">
24			<xsd:selector xpath="ref"/>
25			<xsd:field xpath="."/>
26		</xsd:keyref-->
27	</xsd:element>
28
29</xsd:schema>
30