Bers, Victor. 2009. Genos Dikanikon: Amateur and Professional Speech in the Courtrooms of Classical Athens. Hellenic Studies Series 33. Washington, DC: Center for Hellenic Studies. http://nrs.harvard.edu/urn-3:hul.ebook:CHS_Bers.Genos_Dikanikon.2009.
Chapter 1: The Challenge of Court Speech
The variations are not significant; e.g. Anaximenes in the Rhetorica ad Alexandrum  uses the words dêmêgorikon, epideiktikon, and dikanikon. At Phaedrus 261a–b Plato speaks of rhetoric meant for law cases and “addresses to the people,” using for the latter the term dêmêgoria, a word that suggests deliberative speech. But having quoted, or more likely written, a work supposedly in Lysias’ epideictic style in the form of the Erotikos earlier in the dialogue (230e6–234c5), Plato cannot be said to be ignoring that branch of oratory. 
Similarly, Isocrates makes dicanic speech a sort of ostensible “non-style.” He says that among the sorts of discourses that he did not write as a young man were “those that when spoken seem simple and unadorned, such as people skillful in courts teach the young to practice if they want to have the advantage in litigation” (Panathenaicus 1).  Isocrates does at least allow the possibility that the simplicity of the spoken form conceals some artifice, but some ten years earlier in the Panegyricus (4.11) he enunciated a more trenchant opinion:
Still, an idiôtês needing to speak in court might not see his task as one for which he commanded the necessary skills, even if Isocrates thought it required nothing but a “plain” style.