The DC Bar's website is sporting a "Virtual Library" these days. Most significantly, it includes a lengthy treatise on the Law of Lawyering, courtesy of the law firm of Covington & Burling, described as follows:
This publication, written by D.C. Bar member David B. Isbell, is a comprehensive analysis of the D.C. Rules of Professional Conduct, which governs the ethical practice of law in the District of Columbia, as well as the attorney discipline system upholding those rules. Published 2004. Updated in part, March 2007, following amendments to the Model Rules in 2002 and 2003 and the D.C. Rules of Professional Conduct effective February 1, 2007.
This reference should be among those consulted by any D.C. lawyer researching an ethical issue.