Controls how unknown tags are handled. If set to false, HTMLToWord will throw an HTMLToWordException if it encounters a tag that it does not explicitly know how to handle. If set to true, HTMLToWord will attempt to process the tag. See the IncludeContentsOfUnknownTags for further user-controlable behavior.

public boolean AcceptUnknownTags{ get; set; }
Public Property AcceptUnknownTags() As Boolean
  //--- Create the HTMLToWord object
  HTMLToWord h2w = new HTMLToWord();

  //--- Set HTMLToWord to throw an exception if there are any tags
  //--- in the XHTML fragment that are not explicitly handled.
  h2w.InsertProperties.AcceptUnknownTags = false;

  '--- Create the HTMLToWord object
  Dim h2w As New HTMLToWord()

  '--- Set HTMLToWord to throw an exception if there are any tags
  '--- in the XHTML fragment that are not explicitly handled.
  h2w.InsertProperties.AcceptUnknownTags = False