In order to add your statement,
you will have to print and mail your tax return. You can't attach general
footnotes to the electronic returns, unfortunately. The IRS does not allow general notes from taxpayers for electronic
returns. And in
fact, they don't really want any general footnotes attached... if there is
anything unusual on your tax return about business expenses, they will
ask for it if necessary. Otherwise, you don't have to send it.
Note: The IRS has very specific attachments that are
required to be mailed while sending the actual return electronically. They are
listed on Form 8453 (link below). The IRS specifically states: "Do not attach any form or document
that is not shown on Form 8453 next to the checkboxes. If you are required to mail in any documentation
not listed on Form 8453, you cannot file the tax return electronically."
https://www.irs.gov/pub/irs-pdf/f8453.pdf
