If you're reporting on revenue earned from invoiced items, to avoid overvaluing your figures, you may wish to exclude invoices which have been credit noted.

Take a look at the following example. We've started with a prepopulated report based on Invoices and we're interested in the Gross column as this represents our incoming, however, so that we know how much cash has been truly invoiced, we'd like to ensure that those invoiced items with a corresponding credit note are omitted. 

To do this, firstly - to illustrate the rows we need to exclude - lets add an additional column for Related Credit Notes > Object reference and description.

With this column added, we can easily identify any invoices with corresponding credit notes.

Now we simply add a criteria on this new column so that our report only returns rows where the Related Object reference and description is blank, i.e., rows where a corresponding credit note does not exist. 

To yield the final report below. Note how the total Gross value has decreased to represent the amount which has been truly invoiced.