sui ge·ner·is /'sü-ˌī-'je-nə-rəs, 'sü-ē-/ adj [Latin, of its own kind]: constituting a class alone: unique or particular to itself
the lawyer's...ad that makes no distinction among various legal and factual nuances in each sui generis case has the potential to mislead — National Law Journal
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.