"limited, confined," 1830, past-participle adjective from restrict. Of government documents, etc., "secret, not for public release" it is recorded from 1944. Related: Restrictedly. The older adjective was simply restrict. In mid-20c. U.S., restricted was a euphemism for "off-limits to Jews" (1947).
Manager: "I'm sorry, Mr. Marx, but we can't let you use the pool; this country club is restricted."
Groucho: "Well, my daughter's only half-Jewish; could she go in up to her knees?" [there are many versions and variations of this story in print, some referencing a son instead, dating to his obituaries in 1977]