Hi Tim,If you look in the report you'll see that these fields have the name "Document_"+[AttributeName], e.g. "Document_Project_Title", "Document_Client" etc. They take their values from attributes of the document with the corresponding names, thus if you have an attribute stored in the document called Client, its value will appear in the report.
Since a Title Block is a symbol within, and therefore a child of, the document, its values will not appear in the document fields of the report.