This document includes confidential, proprietary, and commercially/competitively sensitive information not publicly available. We provide this information to [client name here] in strict confidence solely for the purposes of bid evaluation, and on the understanding that it will be safeguarded from intentional or inadvertent release to our competitors, actual or potential.
There. That ought to do it, yeah?
This is the more-or-less standard confidentiality rider in the footer of every proposal I’ve ever worked on. Its purpose is to protect a company’s true technical secrets, pricing strategy, and other good stuff that you wouldn’t want your competitors to know.
Does it work? Well, this article suggests not, or not as well as you might assume. It views the risks arising from Freedom of Information legislation as one of the costs of doing business with the public sector.
I’m not a lawyer, but I suggest you consult one before bidding again. And show them this article. No matter how lovingly crafted, a footer does not trump legislation.