Depending on rank, botanical names may be in one part (genus and above), two parts (various situations below the rank of genus) or three parts (below the rank of species). The names of cultivated plants are not necessarily similar to the botanical names, since they may instead involve "unambiguous common names" of species or genera. Cultivated plant names may also have an extra component, bringing a maximum of four parts:      A botanical name in three parts, i.e., an infraspecific name (a name for a taxon below the rank of species) needs a "connecting term" to indicate rank. In the "Calystegia" example above, this is "subsp.", for subspecies. In botany there are many ranks below that of species (in zoology there is only one such rank, subspecies, so that this "connecting term" is not used in zoology). A name of a "subdivision of a genus" also needs a connecting term (in the "Acacia" example above, this is "subg.", subgenus). The connecting term is not part of the name itself. A taxon may be indicated by a listing in more than three parts: ""Saxifraga aizoon" var. "aizoon" subvar. "brevifolia" f. "multicaulis" subf. "surculosa" Engl. & Irmsch." but this is a classification, not a formal botanical name. The botanical name is "Saxifraga aizoon" subf. "surculosa" Engl. & Irmsch. ("ICN" Art 24: Ex 1). Generic, specific, and infraspecific botanical names are usually printed in italics. The example set by the "ICN" is to italicize all botanical names, including those above genus, though the "ICN" preface states: "The "Code" sets no binding standard in this respect, as typography is a matter of editorial style and tradition not of nomenclature". Most peer-reviewed scientific botanical publications do not italicize names above the rank of genus, and non-botanical scientific publications do not, which is in keeping with two of the three other kinds of scientific name: zoological and bacterial (viral names above genus are italicized, a new policy adopted in the early 1990s).