XSD:PATTERN question

[Andy H]

Could someone please explain what the following XSD extract does:

<xsd:simpleType name="registration">

• <xsd:restriction base="xsd:string">
  <xsd:pattern value="[0-9]{1,8}[A-Wa-w][TWXtwx ]?" />
  <xsd:pattern value="[7-9][A-Wa-w][0-9]{5}[A-Za-z]" />

Thanks