Via the (new) legal writer, Raymond Ward writes about defining the terms of art.
Legal writers often must use terms of art—technical words or phrases unique to a profession. Sometimes these terms come from the legal profession; sometimes they come from other professions, such as medical or engineering. But they all have one thing in common: not everyone knows what they mean. So to make sure that your reader understands a term of art in your writing, define it.
You can define terms of art unobtrusively, without interrupting the flow of your writing. To learn how, read Robert Fugate’s recent article in the Texas Bar Journal, Defining Terms of Art in Legal Writing.