The <Related_URL> field specifies links to Internet sites that contain information related to the service as well as related Internet sites such as project home pages, related data archives/servers, metadata extensions, direct links to online software packages, and web mapping services. The <Related_URL> field consists of

• <URL_Content_Type> Describes the type of resource being referenced by the URL. The <URL_Content_Type> is selected from a list of controlled URL content type keywords and consists of:
• <Type> Describes the type resources being referenced by the URL.
• <Subtype> Describes the subtype of the resource being referenced by the  URL.
• <URL> is the URL to the resource associated with the data service.
• <Description> provides information about the resource defined by the <URL>.

<Related_URL>
    <URL_Content_Type>
      <Type>Related URL Type keyword</Type>
      <Subtype>Related URL Subtype keyword</Subtype>
    </URL_Content_Type>
    <URL>URL up to 600 characters</URL>
    <Description>Text</Description>
  </Related_URL>

• <Description> may contain multiple lines. Characters may be selected from the UTF-8 character set.

• The <Related_URL> field is highly recommended and may be repeated.
• The <URL_Content_Type> and <URL> fields are required.
• The <URL_Content_Type> subfields <Type> and <Subtype> must be selected from the set of URL Content Type keywords. <Subtype> is not required.
• The <URL> subfield may be repeated within the <Related_URL>.
• The <Description> subfield is optional and may not be repeated.

<Related_URL>
    <URL_Content_Type>
      <Type>GET SERVICE</Type>
      <Subtype>GET SOFTWARE PACKAGE</Subtype>
    </URL_Content_Type>
    <URL>ftp://ftpext.usgs.gov/pub/cr/mo/rolla/viewers/dlgv32pro/dlgv32_pro_usgs_setup.exe</URL>
    <Description>
         Download site for DLGv32 Pro spatial data viewing software format.
      </Description>
</Related_URL>