Inventory.xsd

<?xml version="1.1" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" version="1.1" targetNamespace="https://example.com/inventory" xmlns="https://example.com/inventory" elementFormDefault="qualified">

  <!--
    Entry point
  -->
  <xs:element name="inventory">
    <!-- Add an on-hover annotation for this element -->
    <xs:annotation>
      <xs:documentation>
        An inventory of things that a person might own
      </xs:documentation>
    </xs:annotation>

    <!-- Define the type of the element, in this case only a "garage" child is allowed -->
    <xs:complexType>
      <xs:sequence>
        <xs:element ref="garage"></xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>

  <!-- Define a garage element, referenced from "inventory" -->
  <xs:element name="garage">
    <!-- Add an on-hover annotation for this element -->
    <xs:annotation>
      <xs:documentation>
        A collection of vehicles that a person owns
      </xs:documentation>
    </xs:annotation>

    <!-- Define that any amount of "car", "bicycle" or "motorbike" elements are allowed as children -->
    <xs:complexType>
      <xs:choice maxOccurs="unbounded">
        <xs:element ref="car"></xs:element>
        <xs:element name="bicycle"></xs:element>
        <xs:element name="motorbike"></xs:element>
      </xs:choice>
    </xs:complexType>
  </xs:element>

  <!-- Define a car element -->
  <xs:element name="car">
    <!-- Add an on-hover annotation for this element -->
    <xs:annotation>
      <xs:documentation>
        A motorcar, you know, with wheels
      </xs:documentation>
    </xs:annotation>

    <!-- Define the allowed attributes of a "car" -->
    <xs:complexType>
      <xs:attribute name="name" type="xs:string" use="required" />
      <xs:attribute name="wheels" type="xs:integer" />
    </xs:complexType>
  </xs:element>

</xs:schema>