Can you modify the SOP Invoice to group the line items by item class code with a header for each group?
To do this kind of modification. I would suggest generating invoices using a different tool.
Accountable Forms Printer will allow you to create an invoice layout in either Crystal Reports or in SSRS that can be grouped the way you want. With this tool, your users simply print an invoice like they do today.
Version 2010 provided a way to generate reports using MS Word and might allow this. Version 2013 provides additional options. (Check out our book Version 2013 Unleashed for details.)
You will need to create a sort by item class and then create an additional header section to break on the item class.
Thank you Leslie. That was helpful. Now I have the report grouping and subtotaling correctly, but there is a page break after each item class. I have no page break on the footer and am puzzled as how to get rid of it. Needless to say, I'm not a report writer expert.