The abbreviation cf. (short for the Latin: confer/conferatur, both meaning "compare") is used in writing to refer the reader to other material to make a comparison with the topic being discussed. Style guides recommend that cf. be used only to suggest a comparison, and the word "see" be used to point to a source of information.
In biological naming conventions, cf. is commonly placed between the genus name and the species name to describe a specimen that is hard to identify because of practical difficulties, such as poor preservation. For example, "Barbus cf. holotaenia" indicates that the specimen is in the genus Barbus and believed to be Barbus holotaenia, but the actual species-level identification cannot be certain.
Cf. can also be used to express a possible identity, or at least a significant resemblance, such as between a newly observed specimen and a known species or taxon. Such a usage might suggest a specimen's membership of the same genus or possibly of a shared higher taxon. For example, in the note "Diptera: Tabanidae, cf. Tabanus", the author is confident of the order and family (Diptera: Tabanidae) but can only suggest the genus (Tabanus) and has no information favouring a particular species.
- "cf". Cambridge Advanced Learner's Dictionary & Thesaurus. Cambridge University Press. n.d. Retrieved October 30, 2016.
- "Latin Terms and Abbreviations". The Writing Center at UNC-Chapel Hill. The University of North Carolina at Chapel Hill. n.d. Retrieved October 30, 2016.
- "Chicago Manual of Style 15th Ed. Style Sheet" (PDF). Michigan State University Press. p. 6, citing Chicago Manual of Style section 16.58. Archived from the original (PDF) on December 23, 2015. Retrieved July 7, 2016.
There is a distinction between see and cf.; use cf. only to mean 'compare' or 'see, by way of comparison'.
- Bengtson, Peter. "Open Nomenclature" (PDF). Palaeontology. Archived from the original (PDF) on April 2, 2015. Retrieved March 19, 2015.
- Hartmann, Anne (February 2007). "Field Key for Selected Benthic Invertebrates from the HKH Region" (PDF). Draft Version. Retrieved October 30, 2016.
- The dictionary definition of cf. at Wiktionary