To have an effect, this property must be set before CreateDocument(String, Byte) is called.
To have an effect, RenderOnDemand must be true; otherwise, thumbnails will not be grouped.
This property will be ignored if AllowFindMatchingPdf is true and the PDF referenced by CreateDocument(String, Byte) was previously loaded. (The value of this property when the PDF was originally loaded by CreateDocument(String, Byte) will instead be used)
RAD PDF prior to version 2.22 did not support this feature. All documents created with version 2.21 and earlier will behave as if this property is false.
At this time, you can not append documents using a Document ID if this property is true.