Article: Open nomenclature
Open nomenclature plays an important role in taxonomic decisions by palaeontologists, but usage and interpretation of the signs employed vary considerably. Prevailing fashion seems to favour aff. to indicate affinity of a potentially new, as yet undescribed species with a known species, whereas cf. and ? indicate uncertainty. Use of aff., cf., and ? for different degrees of uncertainty, as recommended by some workers, leads to instability in interpretation. Abbreviated taxonomic expressions such as 'Trichiurus cf. lepturus' are unambiguous and are to be preferred to 'Trichiurus cf. T. lepturus'. Careful, judicious use of open nomenclature is to be encouraged and should be covered by the International Code of Zoological Nomenclature. A set of recommendations is given.