The results of the billing page are presented as an invoice.  The Invoice header comes from the Company profile.  The Bill To comes from the data found on the Bill To page of an ticket.  The Invoice line item(s) come from the Sales page of a ticket.

The invoice is available as an attachment on the email page.  The Invoice is presented in a PDF format.

A Bid, Proposal or Receipt use the same data.  The title is the only item changed.