A set of blocks, also called a Resolution Class, that partition the set , where is a balanced incomplete Block Design.
See also Block Design, Resolvable
References
Abel, R. J. R. and Furino, S. C. ``Resolvable and Near Resolvable Designs.''
§I.6 in The CRC Handbook of Combinatorial Designs
(Ed. C. J. Colbourn and J. H. Dinitz). Boca Raton, FL: CRC Press, pp. 87-94, 1996.