Groklaw presents "A Brief Description of Citators for Those Without a Legal Background" by Mark Giangrande.
Mark Giangrande is a lawyer and member of the Illinois Bar. He currently works as a reference librarian at the Vincent G. Rinn Library at the DePaul University College of Law in Chicago. He is also the editor of the Tech Law Prof Blog and a co-editor of the Law Librarian Blog.
Thanks to the Law Librarian Blog for the tip.