My.Vendor:Document.WithReferences:
  superTypes:
    Neos.Neos:Document: true
  references:
    myReference:
      constraints:
        nodeTypes:
          '*': false
          'Neos.Neos:Document': true
        maxItems: 1
      scope: node
      ui:
        label: 'My reference'
        inspector:
          group: default
          editorOptions:
            nodeTypes:
              - Neos.Neos:Document