reference - XSD: What schema authors mean when referencing xs:schema as element in payloads? - Stack Overflow

For work, I'm generating WSDL payloads from third-party schemas for testing purposes.

Occasionally, the schema contains an element that references the XSD schema element itself, like below:

        <s:element maxOccurs="1" minOccurs="0" name="FindCustomerByRuleEx_CIIResult">
           <s:complexType>
              <s:sequence>
                 <s:element ref="xs:schema"/> <!-- huh? -->
                 <s:any/>
              </s:sequence>
           </s:complexType>
        </s:element>

It is not an isolated instance. I've seen it in at least three WSDLs from different vendors.

The generator I use has no issues with this. It does create an element of type {}schema inside the payload. The payload, though, becomes unnecessarily bigger, not to mention that it makes little sense.

What I'm trying to figure out is this:

What the designers of the schema MEANT by this declaration?

Why would a payload include an xs: schema element? Maybe they meant "any XSD type"? Maybe it is some obscure early-days-of-WSDL convention that I'm not aware of? Maybe it is a known bug in an XML authoring tool (which one)?

Does anyone have any insight into this?

Thank you!