<?xml version="1.0" encoding="UTF-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="mission" type="MissionType"></xs:element> <xs:complexType name="MissionType"> <xs:all> <xs:element name="name" type="xs:string" minOccurs="0" maxOccurs="1"></xs:element> <xs:element name="description" type="xs:string" minOccurs="0" maxOccurs="1"></xs:element> <xs:element name="url" type="xs:string" minOccurs="0" maxOccurs="1"></xs:element> </xs:all> <xs:attribute name="id" type="xs:ID" use="required" /> </xs:complexType> </xs:schema>