Dear Jessalynn, I am far from being a liturgical expert, but when I have need of just such information, I can usually find it in Andrew Hughes, Medieval Manuscripts for Mass and Office: A Guide to their Organization and Terminology (University of Toronto Press, 1982; pb 1995). Just as an example, the index contains 8 references to "versicle". Hope this helps. Jim Bugslag %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%