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.
Main article: Open nomenclature
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.
There is a distinction between see and cf.; use cf. only to mean 'compare' or 'see, by way of comparison'.