Lawyers write memos to other lawyers and the clients to tell them the answer to questions. The most common format is:

• Question presented -- one sentence, maybe two

• Short answer -- Ideally yes or no, but usually a couple sentences.

• Facts -- A description of all of the background behind the question

• Analysis or discussion -- The reasoning to get from the question, contextualized by the facts, to the answer

• Conclusion -- A plea for more billable hours. Ahem. I mean a statement of your level of certainty with respect to your answer, and avenues of research that would lend more certainty.

I've heard of this format as being called IRAC -- issue, rule, analysis, conclusion (where the facts get thrown into the analysis).

Within the analysis, there are many ways of organizing the material, many of which I think are partially redundant of the format of the memo. Here's an example: http://www.law.cuny.edu/legal-writing/students/memorandum/memorandum-1.html.

Max L.