<xs:complexType name="OsobaTyp">
    <xs:sequence>
        <xs:element ref="imie" minOccurs="1" maxOccurs="unbounded"/>
        <xs:element ref="nazwisko"/>
    </xs:sequence>
    <xs:attribute ref="plec" use="required"/>
    <xs:attribute ref="email" use="optional"/>
</xs:complexType>

<xs:simpleType name="PlecTyp">
    <xs:restriction base="xs:string">
        <xs:enumeration value="k"/>
        <xs:enumeration value="m"/>
    </xs:restriction>
</xs:simpleType>