XML : Is maxoccurs needed for complex types in XML?

Given:

  <?xml version="1.0" encoding="utf-8"?>  <Clients xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">    <FileDate>2016-10-12</FileDate>    <Client>      <Record_ID>        <ClientCode>400057</ClientCode>      </Record_ID>      <Address>        <AddressLine1>Dynamic Funds Tower</AddressLine1>      </Address>      <Notes>        <Note>          <Add_Date>10/5/2016 3:13:22 PM</Add_Date>          <Add_User>rthomas</Add_User>          <Change_Date>10/6/2016 12:19:02 PM</Change_Date>          <Change_User>Daniel</Change_User>          <Text>This is a note</Text>        </Note>      </Notes>    </Client>    <Client>      <Record_ID>        <ClientCode>101134</ClientCode>      </Record_ID>      <Address>        <AddressLine1>100 North Michigan</AddressLine1>      </Address>      <Notes>        <Note>          <Add_Date />          <Add_User />          <Change_Date />          <Change_User />          <Text />        </Note>      </Notes>   </Client>  <Client>      <Record_ID>        <ClientCode>101628</ClientCode>      </Record_ID>      <Address>        <AddressLine1>900 Third Avenue, 30th Floor</AddressLine1>      </Address>      <Notes>        <Note>          <Add_Date>10/5/2016 3:13:22 PM</Add_Date>          <Add_User>rthomas</Add_User>          <Change_Date>10/6/2016 12:19:02 PM</Change_Date>          <Change_User>Daniel</Change_User>          <Text>This is a note</Text>        </Note>      </Notes>    </Client>  </Clients>    as the XML source AND:    <?xml version="1.0"?>  <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" attributeFormDefault="unqualified" elementFormDefault="qualified" version="1.0">      <xsd:element name="Clients" />      <xsd:element name="FileDate" type="xsd:date" />      <xsd:element name="Client">          <xsd:complexType>              <xsd:sequence>                  <xsd:element name="Record_ID">                      <xsd:complexType>                          <xsd:sequence>                              <xsd:element name="ClientCode" type="xsd:string" />                          </xsd:sequence>                      </xsd:complexType>                  </xsd:element>                  <xsd:element name="Address">                      <xsd:complexType>                          <xsd:sequence>                              <xsd:element name="AddressLine1" nillable="true" type="xsd:string" />                          </xsd:sequence>                      </xsd:complexType>                  </xsd:element>                  <xsd:element name="Notes">                      <xsd:complexType>                          <xsd:sequence>                              <xsd:element name="Note" nillable="true" >                                <xsd:complexType>                                 <xsd:sequence>                                     <xsd:element name="Add_Date"    nillable="true" type="xsd:string" />                                     <xsd:element name="Add_User"    nillable="true" type="xsd:string" />                                     <xsd:element name="Change_Date" nillable="true" type="xsd:string" />                                     <xsd:element name="Change_User" nillable="true" type="xsd:string" />                                     <xsd:element name="Text"        nillable="true" type="xsd:string" />                                 </xsd:sequence>                                </xsd:complexType>                              </xsd:element>                          </xsd:sequence>                      </xsd:complexType>                  </xsd:element>              </xsd:sequence>          </xsd:complexType>      </xsd:element>  </xsd:schema>    

Does Client require a maxoccurs value to allow more than one client in the XML file. Every validator I can find validates an XML with multiple clients, yet maxoccurs is not used. Further, Note does not appear to require maxoccurs either. Is this because it is a complex type?