White fonting is the practice of inserting hidden keywords into the body of an electronic document, in order to influence the actions of a search program reviewing that document.
White fonting can be used as a search engine optimization (SEO) technique in webpages, by inserting the same keyword multiple times, to create a higher ranking in search engine results where Keyword density is a factor.
[1] White fonting can also add unrelated, but often searched, keywords to a webpage in order to gain additional traffic.
White fonting is considered to be an unethical search engine optimization technique, because pages containing white fonting are not indexed and ranked on the basis of page content viewable by human readers.
[2] White fonting can also be used to boost the visibility of other electronic documents evaluated by search engines or automated tracking software, such as resumes or reports.