You can use a locator (for example a barcode locator) to establish document boundaries in preparation for document classification later down the line. The recommended solution is to add locator(s) to a "dummy" class (called for example DocSep) that is used exclusively for document separation and excluded from the classification phase. You can run the locators on this class before separation occurs and use the results to explicitly set the boundaries.

Use the Document_BeforeSeparatePages script hook which fires before any page classification or separation occurs.

' Project Script

Private Sub Document_BeforeSeparatePages(ByVal pXDoc As CASCADELib.CscXDocument, ByRef bSkip As Boolean)

   Dim oTmpXDoc As CscXDocument

   'Declaration required if separation locator requires OCR
   'You must also add the Kofax Memphis Forms 4.0 reference from Edit | References...
   'Dim PageRecognizer As New MpsPageRecognizing

   Dim lPage As Long
   For lPage = 0 To pXDoc.CDoc.Pages.Count-1

      'For locators requiring OCR: You must call OCR directly with the following line
      'PageRecognizer.Recognize pXDoc, Project.RecogProfiles.ItemByName("FineReader"), lPage

      'Create a temporary document containing only this page
      'and run locators from 'DocSep' class on that document.
      Set oTmpXDoc = New CscXDocument
      oTmpXDoc.CopyPages pXDoc, lPage, 1
      Project.ClassByName("DocSep").Extract oTmpXDoc

      'Get the locator results
      Dim oLocator As CscXDocField
      Set oLocator = oTmpXDoc.Locators.ItemByName("BL_Barcode")

      Dim lAlt As Long
      For lAlt = 0 To oLocator.Alternatives.Count-1
         'Check a confident alternative is found on the current page
         If oLocator.Alternatives(lAlt).Confidence > 0  Then
            'Directly set the separation boundary
            pXDoc.CDoc.Pages.ItemByIndex(lPage).SplitPage = True
         End If
      Next

   Next

End Sub