@AttachmentModifiedTimes
If you then attach the whitepaper.pdf file to the second rich text field and refresh the document, the computed field changes to display 09/25/2001;05/10/2001. Attaching the myreport.wk1 file to the first rich text field and refreshing the document causes the computed field to return 09/25/2001;05/10/2001;09/26/2001.