The abbreviationcf. (short for eitherLatinconfer orconferatur, both meaning 'compare')[1] 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 words "see" or "vide" be used generally to point to a source of information.[2][3] InItalian, the abbreviation "cfr." (confronta, 'confront') is more common than "cf.".[4]
In biological naming conventions, cf. is commonly placed between thegenus name and thespecies 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 genusBarbus and believed to beBarbus holotaenia, but the actual species-level identification cannot be certain.[5]
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 knownspecies ortaxon.[5] 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.[6]
Amongnumismatists (coin collector-research specialists), cf. may be used in references on the paper and/or online coin identification information meaning "compare to". It is common for abbreviations of listings in trusted coin catalogues or sales from certain online auctions to be cited when identifying a particular coin. If the specimen in question is not an exact match but comes close to a known source, cf. may be used.[citation needed]
There is a distinction between see and cf.; use cf. only to mean 'compare' or 'see, by way of comparison'.
The dictionary definition ofcf. at Wiktionary