Here's a question that I posed to Erin McKean, and that she graciously agreed to answer in the next few days.
The general question is: How do (and should) lexicographers decide whether to include a word in the dictionary?
The concrete example, contributed by Widener lawprof Ben Barros, is offered by the words "inartful" and "inartfully." Prof. Barros and I were both shocked to learn that the two words weren't in the OED or any dictionary accessible via onelook.com.
Some 20 years ago, William Safire wrote about inartful, and said "it is not a word." But of course that's wrong: It's a word that lawyers use often, though generally without recognizing it as legalese, and that nonlawyers seem to use on occasion as well.
A Lexis search through MEGA;MEGA for inartful! and date(> 1/1/2007) uncovers over 600 uses this year alone. Searches for past uses reveal published cases or summaries of lawyers' arguments using that term dating back to 1832. A search through a database of scanned 1700s English books found references from 1751 (Edward Kimber's The Life and Adventures of Joe Thompson 244 (2d ed.)) and 1759 (Samuel Derrick's [?] A General View of the Stage 26 (1759)). Kimber used it to mean "artlessly," but Derrick used it to mean "unskillfully," which seems to be the dominant modern meaning.
For whatever it's worth, unartful and unartfully do appear in Webster's 1913 Revised Unabridged Dictionary, though Google suggests that unartfully is over 30 times less common than inartfully.
So my questions to Ms. Mckean: Any thoughts on why the word isn't in the dictionaries, how lexicographers would decide whether to include it, and what people should do in the meantime?