What is "#additional invoice note each line" for?

That setting is located at /admin/erpal/invoice

Under "Tax rates" section

The help text reads: Syntax is vat_value#vat_display_label#additional invoice note each line

We understand the first item is the tax value Syntax is vat_value. The second item is the display value vat_display_label. But what is the third item for? additional invoice note each line We searched but found nothing. Also searched the output .pdf invoice. Based on the help text it sounds like it would allow user to add some kind of note to the invoice? Per line? Could you give us an example? If it's display somewhere. Then where?

12#12% (7% PST and 5% GST)#what is this third item for?
0#0% Tax included#what is this third item for?