These proposals are formal documents which propose a plan or idea to the sales department head and are often accompanied with sales proposal cover letters. (sampletemplates.org)
You can not refer to the explanations in this site in formal documents of a company, or prove this site has promoted this idea. (law.stackexchange.com)
This way, you've essentially given the employer the option to look at just one or both, and you have included the more formal document as an attachment. (career.vt.edu)