Referencing option causes the output of the list of objects referencing the current one – e.g.  ../do.ashx?cmd=objsnav&ids=5875&options=referencing produces:

  <article nav:objectType="article" id="obj5875" . . . >

    <nav:objectTypeAttrs . . ./> 

    <nav:referencing>

      <nav:referencingBy attrName="pubDest.objs" /> 

      <nav:referencingBy attrName="task.products" /> 

      <nav:referencingBy attrName="extDoc.articles" /> 

    </nav:referencing>

    <folderRef idref="obj8">

    . . .

  </article>

This option is enabled by default for the backward-compatibility.