Often when I see "de facto" written somewhere it is in italic. For example:
LaTeX is a high-quality typesetting system; it includes features designed for the production of technical and scientific documentation. LaTeX is the >>> de facto <<< standard for the communication and publication of scientific documents. LaTeX is available as free software.
Continued practices of expecting African Americans to ride in the back of buses or to step aside onto the street if not enough room was present for a Caucasian person and "separate but equal" facilities are instances of >>> de facto <<< segregation.
Why?