A.R.S. § 12-3101 applies to Title 12, Chapter 22 of the the Arizona Revised Statutes (A.R.S. § 12-3101-3103), which addresses the application of foreign laws by Arizona courts and other adjudicative bodies. This statute defines the term "foreign law" as used in that Chapter of the Arizona Code:
In this chapter, unless the context otherwise requires, "foreign law" means any law, rule or legal code or system other than the constitution, laws and ratified treaties of the United States and the territories of the United States, or the constitution and laws of this state.
Of course, definitions like this are often the subject of much interpretation themselves, and if you believe this statute may apply to a legal situation you are involved in you should discuss the matter with an attorney as soon as possible.