One of the oldest applications of linguistics to legal issues is in disputes that involve commercially used names, phrases and symbols in which individuals and companies have proprietary rights defined by law and international treaties. Linguists (especially those with expertise in lexicography, lexicology and onomastics) advise lawyers and sometimes present evidence in courts that seek to ascertain the linguistic bases for the legal viability of trademarks and similar signifiers (called ‘marks’ in general). Questions and controversies of linguistic interest arise in four chief areas for which various methodologies have been established. First, if two marks are phonologically and semantically so similar that a significant likelihood of confusion of the two may be created, then one must be abandoned. Second, no mark may be ‘generic’ (e.g., dog food) nor merely ‘descriptive’ (e.g., healthy) unless truly famous (e.g., General Foods). Third, trademarks must meet various standards of propriety. Fourth, a trademark may not ‘dilute’ an established, famous trademark. The forensic use of linguistics in trademark disputes is especially common in North America (and more rarely in Australia and Chile), though Japanese linguists have been active in studying trademarks as pragmatic entities.