Meme: Inigo Montoya, You keep on using that Latin abbreviation. I do not think it means what you think it means.

Friends don’t let friends use “cf.”

(My writing pet peeves, part 2)

Scientific writing is sprinkled with Latin.  Yes, there are “Latin” (or “scientific”) names of organisms, and those can be unexpectedly fascinating; but that’s not my topic today.  Instead, it’s those little words and phrases, often abbreviated: i.e., e.g., versus, sensu lato. Danger lurks for those who don’t use them carefully – and it lurks in cf. especially, it seems. In fact, the misuse of cf. is high on my list of writing pet peeves. It also carries a broader lesson, which I’ll get to.

So what’s the problem with cf.It’s that I frequently see it used as if it means “see also”, or just “see” – but it doesn’t.  It’s actually an abbreviation of the Latin conferre*, literally “bring together”.  It means “compare”, and in particular it suggests that the reader can see the writer’s point by bringing together (to compare or contrast) two or more things that follow the “cf.”.  For example, I might write “While theory confirms that attack by specialist parasitoids can cause herbivore populations to cycle, authors have differed as to whether parasitoid-attack data for spruce budworm are consistent with this mechanism (cf. Smith 2014, Jones 2016)”. This is more specific than writing “e.g., Smith 2014, Jones 2016” or “see Smith 2014, Jones 2016”, in that it identifies the contrast between those two citations as the point of interest.

So that’s what cf. means – except that in an important sense it doesn’t, or at least, not any more.  That’s the broader point I promised.  What a word “means” is just a convention shared by a set of readers about the information conveyed by its use. Those conventions are sometimes strong (with virtually everyone assigning the same meaning to a word) and sometimes weak (with a single word having multiple meanings, some more familiar than others). To make matters worse, meanings can evolve and sometimes even reverse over time: for example, a counterfeit was once a genuine copy. The meaning of counterfeit has now stabilized and would confuse a reader only if you tried to use its original sense.  Cf., in contrast, is probably best seen as currently in a state of rapid semantic drift, with no consensus about its meaning.  As a result, it doesn’t matter whether you use cf. in its “correct” sense or its “incorrect” one – some readers will misunderstand.

Of course, cf. is not drifting alone.  The same is true, for example, of a moot point – some readers will assume you mean a point open to debate (the original meaning), others will assume you mean a point irrelevant to the matter at hand (the more common meaning now), and still others will just be puzzled.  Better to avoid the problem: friends don’t let friends use cf. because as long as its meaning hasn’t stabilized, it’s an ineffective tool for communication. Ditto for moot point, and beg the question for that matter, and if you have a favourite example, please leave it in the Replies.

Semantic drift is, by the way, a normal part of linguistic evolution.  It’s easy to decry the ruin of our language at the hands of its ignorant butchers, but those who do so are just betraying their own naïveté about how language changes as people use it.  Just like counterfeit, cf. and moot point may soon be useful words again; it’s just awkward that we’re living through the period in which they’re changing too quickly for reliable use**.

Since we’re on the topic, other Latin tidbits get misused too, albeit not so egregiously.  Here’s a quick rundown of some common*** Latin words and phrases. These aren’t mid-semantic drift; they’re just tricky.  That means there’s a clear “correct” way to use them, and it’s perfectly fine to do so. (Overusing them can make text sound stuffy and pendantic, though.)  By the way, italicization of Latin borrowings is a common but not universal convention; check journal style.

  • ca. or c. (circa): “around” (temporally) or “approximately”
  • etc. (et cetera): “and so on” (surely the least troublesome, but I have no idea why it’s abbreviated as if it were a single word)
  • et al. (et alii): “and others”, referring to people, and used routinely to abbreviate author lists. Note there’s no period after et, only after al, because et is a complete word. (‘Period’ in North America, ‘full stop’ in British usage – because English wasn’t complicated enough without another set of arbitrary differences….)
  • e.g. (exempli gratia): “for example”
  • i.e. (id est): “that is” (note that e.g. and i.e. are not interchangeable)
  • f./ff. (folio/folii): “and following”, referring normally to page numbers. 226f. would mean 226-227, while 226ff. would mean 226 and at least two more pages.
  • ibid. (ibidem): “in the same place”, used to cite the same work most recently cited (common in arts and humanities, but rarely used in science).
  • n.b. (nota bene): “take notice”, or “this is important”
  • sensu X: “as used by person X”, indicating you intend a term to mean what X meant by it (common in but not exclusive to systematics)
  • sensu stricto (s.s.): “in the strict sense”
  • sensu lato (s.l.): “in the broad sense” (s.s. and s.l. are most common in systematics, where they refer to stricter or broader circumscriptions of genera, etc.)
  • vs. (versus): “as opposed to”, “or in contrast to”

There. Sorting out cf. and its brethren may not change the world, but I’ll sleep better tonight. Such is the life of the word nerd.

And I’ll leave you with this, courtesy of Alex Bond (@TheLabAndField).  You did click on that link under “et al.“, right?  Well, if my little musical pun wasn’t enough for you, here goes Alex:

A man walks down the street
He says why am I author in the middle now
Why am I stuck in the middle
The rest of my pubs are so hard

I need a funding opportunity
I want a shot at publication
Don’t want to end up a buffoon
In a scientific graveyard

Mr. Editor, Editor
Dots in the figures
Far away my well-lit-cited door
Mr. Coauthor, Coauthor
Get these reviews away from me
You know I don’t find this stuff amusing anymore

If you’ll be my referee
I can be your coauthor
I can call you Betty
And Betty when we publish,
You can call me et al.

© Stephen Heard ( June 13, 2016, except parody lyrics by Alex Bond; original lyrics © Paul Simon, of course.

This post was inspired by a Twitter conversation with Alex Bond and Aerin Jacob – thanks to both. It’s based in part on material from The Scientist’s Guide to Writing, my guidebook for scientific writers. You can learn more about it here.

*^Note that it’s an abbreviation of a single word, and thus it’s cf., not c.f. I would love to pretend I hadn’t learned this only now, while working on this very post.

**^It would be interesting to know if the usage frequency of words goes down when rapid semantic drift makes their meaning unclear.  Some linguistics scholar has surely answered that question; but if not, you’re welcome, lingustics-student-looking-for-a-thesis-topic.

***^If these aren’t enough to satisfy your appetite, there are dozens more on this handy Wikipedia page.


45 thoughts on “Friends don’t let friends use “cf.”

  1. Jens Amendt

    Nice tune Stephen, thanks! But: Isn’t cf. an useful (and legal) tool in taxonomy/nomenclature, which you can use when you are not 100% sure that this is e.g. Musca domestica (=> Musca cf. domestica)? So, I still would like to use that abbreviation and introduce it to students.
    But I understand that you are more on a semantic path right now 🙂 Thanks for your nice Blog, by the way.

    Liked by 1 person

    1. ScientistSeesSquirrel Post author

      Hi Jens – good question – I’m not a taxonomy expert. You may be right, all taxonomists may well understand a cf. usage in that sphere. If so, then I’ll have to say “friends don’t let friends use ‘cf.’ – except in taxonomy”!

      Liked by 1 person

    2. Lawrence Kirkendall

      To be more exact (as I understand the practice), one uses cf. domestica to literally mean “someone needs to compare this specimen with type material of domestica because I think it might be that species, but I have not been able to do so as of this writing”. (And what could be more useful than to be able to say all that with two letters and period/full stop?)

      Liked by 1 person

          1. ScientistSeesSquirrel Post author

            Interesting; that’s the first claim I’ve seen for cf. being short for “conformis”, and thus “similar to”. I’ve mostly seen “nr.” for “near” used in that way. It’s not a big distinction in meaning from “compare”, if you take Lawrence’s reading above; but it does muddy the waters even a bit further, doesn’t it?

            Also, the article you link to is amusingly cranky, isn’t it? (Especially the last paragraph). I got a kick out of it. Cheers!


            1. Cesar Crash

              I run an insect blog in Brazil, it’s and I ALWAYS use cf. between the binominal, like, for exemple, Camponotus cf. rufipes, because we can’t really tell the exact species by photos in many groups. What bothers me the most in this article is that it states that I shuld never say Camponotus cf. rufipes. Instead, I should say Camponotus, cf. C. rufipes, because in the International code we have no room to use anything between the generic and the specific names but the subgeneric name. But the article is from 1986, nowadays this is used everywhere. So, my point is, did the rules change, or are we all using it wrong?


              1. ScientistSeesSquirrel Post author

                Ah, sorry Cesar, I misunderstood your point. While I’m not a “real taxonomist”, I use ‘cf’ in writing about species exactly as you do, and I see it very frequently. Similarly, I would not hesitate to write something like this: “This is one of two species of Solidago, either gigantea or brendiae” – which would be similarly illicit by the logic of that 1986 article, I think. I find your usage perfectly clear. I would use it unless a journal editor or copy-editor indicates it violates that journal’s style sheet!


    3. Carol Smith

      Hoi polloi! Now means the complete opposite. I do use cf just to mean compared to and it’s very useful, so I’m just going to keep going. And, I did not know that about moot point, will go to bed ce soir a little less ignorant. Most of my pet peeves are around French, chaise lounge, decolletage, ugh.


  2. ScientistSeesSquirrel Post author

    You’re right, Simon! loc. cit., for loco citado, or “in the place cited” is used in a footnote or endnote to repeat a citation in its entirety, right down to page number. (It’s like ibid. but with extra precision.) Probably sighted only rarely in the scientific literature, but common in the arts.


  3. Peter Erwin

    In his book The Footnote: A Curious History, Anthony Grafton claims that there is a tradition among historians of using “cf.” in the following fashion: “Historians may simply cite a work by author, title, place, and date of publication. But often they quietly set the subtle but deadly ‘cf.’ (‘compare’) before it. This indicates, at least to the expert reader, both that an alternate view appears in the cited work and that it is wrong.”

    Liked by 2 people

    1. jeffollerton

      “Decimate” is an interesting one because its original meaning (to kill one in ten) has changed over time. But then that’s true of so many words and I’d be comfortable with using it to mean “devastate” or “destroy”.


        1. ScientistSeesSquirrel Post author

          I didn’t know the ‘tithing’ sense of ‘decimate’ – thanks, Jeff! My position on decimate, FWIW: it’s a word that has completed its semantic drift (at least for now). If you were to use it in its “kill/destroy 1/10” sense, you’d just confuse your readers; using it to mean “devastate” won’t confuse anyone. I’m going to put that one with “counterfeit” and give it the (entirely worthless) Scientist Sees Squirrel Stamp of Approval.

          Liked by 1 person

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  5. Peter Apps

    “Comparable” is now widely misused as a synonym of “similar” (and very often in a context of “This argument would have been a lot more convincing of these numbers had come out closer than they did”). Comparable means capable of being compared, which in science is equivalent to being expressed in units that can be interconverted. “Three feet” is comparable with “one meter”, which allows us to sensibly say that the two lengths are similar. Three feet is also comparable with 3 microns, or 79.6 million kilometers, but is not similar to either of them, and is not comparable at all with 3 Kilograms even though the two numbers are the same.


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  9. Bruce Fulford

    If people stop using words or abbreviations because of semantic drift, how will they develop a settled meaning? Readers usually understand meanings from context which is how words achieve settled meanings. I say keep using them and let the chips fall where they will.


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  11. christoph westbrook

    I’m very late to this post, but I have the same peeve. But as I get older, I increasingly think that latin abbreviations should be discouraged. If you want to say “for example” just write that and forget “e.g.”. If you want to say “see Jones 2016”, or “compare Jones 2016”, just pick the one you mean and write that. For some people, including my younger self, using latin abbreviations is just showing off some cheap erudition. But if your editee wants to use a latin abbreviation for “see Jones 2016” you can tell them to use “v.” for “vide”.

    Liked by 2 people

  12. Kevin Kelly

    Where did you find that thing about ‘counterfeit’? The earliest meaning in English is ‘fake’ (1340: Þus sal anticrist þan countrefette Þe wondirs of God. OED). As is it in French and medieval Latin. Only in Cassiodorus is the meaning different, apparently ‘setting in opposition, contrast’.


    1. ScientistSeesSquirrel Post author

      Good question – it’s been years since I read that. Closest I can find now is listings for an archaic meaning of simply “a copy” (without the implication of intent to deceive). With luck I’ll rediscover my source…


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    I really enjoyed this article, so enlightening. I’m still feeling that coquille/word ‘pendantic’ like a piece of spinach stuck in my teeth. I’m sure it doesn’t matter a jot and the article is four years old! There’s also linguinistics further down (my neologism). Without nit-pickers and ‘irritating erudites’ just where would we be anyway?! 🙂 Salutations typographiques, Nicolas Jenson, (I would like to think I am ‘hoi polloi’ but I am probably just ‘hoi polloi’… I loved your ‘semantic drift’!)



    As regards the proper use of cf. – I feel like it means: ‘I would refer your honorable Lord to…’ but I’m not a scientist and even less a Latinian so maybe my assertion is maddeningly fanciful and imprecise!



    Bravo on your help with “cf,” but highest marks indeed to your adaptation of a terrific song. Obviously, I sung it to myself whilst reading it the first time.


  18. Ralph Liam

    I’m sad about moot. On my side of the Atlantic, it still retains it’s original meaning of point for discussion – presumably something that was raised in Anglo-Saxon moots. I guess the most familiar moot in modern times is Tolkein’s Entmoot, in which many highly relevant and practical points were discussed. My pet hate amongst linguistic drifts though, is disinterested. It now no longer communicates “interested but impartial” and has merely become synonymous with uninterested.


  19. Alhadis

    I was trying to think of a 2-letter abbreviation that roughly meant “see also:” or “referenced from”, and “cf” was a perfect fit. It was for a bit of code that formats a reference to an external resource (i.e., files and URLs), and its name had a grand character limit of 2 characters (yup, don’t ask…).

    I speak computer better than human nowadays, so this article was a badly-needed refresher. I even bookmarked it, since I know damn well I’ll be consulting that list later…

    — Somebody who needs to read more books


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  21. Lenny

    Somehow in my youth I decided that cf was short for Cross reFerence (which I thought meant “see also”). Thanks for the correction.
    (“Begs the question” is my biggest peeve. I’m trying to get over it. I’ve now heard it misused on NPR and even by my favorite super smart podcaster.)


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  23. Art

    I had been using cf. wrong for the last six years in writing legal briefs, all of a sudden I had a bad feeling when I used it tonight, and googled it and found this page. Thank you so much! (Love the Inigo meme, totally stole it) I checked a legal writing treatise and you are totally correct. The text was useful so thought I would share it.
    California Style Manual (Fourth Addition) p. 9-10:
    When a case is cited as the source of a quotation, or when a case directly supports the proposition stated in the text, no introductory signal is appropriate. Citations to weaker support, however, should be introduced by the word “see.” Thus, “see” should precede citations to cases that only indirectly support the text, citations to supporting dicta, and citations to a concurring or dissenting opinion. Never use “see” to support a direct quote.
    In the latter instances, insert an explanatory parenthetical note indicating “dicta,” “cone. opn.,” or “dis. opn.”. Secondary authority may be introduced by “see,” but need not be.
    The signal “d.” (Latin: confer, meaning “compare with”) is used to introduce a decision that is sufficiently analogous to lend support to the proposition, as where a cited case applies a similar statute. The word “accord” is a signal used after a primary authority has been cited, and introduces decisions, including those from other jurisdictions, holding squarely in accord. “Accord” is also used when the author wishes to quote from one opinion and then cite other supporting authorities.
    To contrast decisions, use the form “Compare … with …. ” To cite cases squarely to the contrary of the proposition stated, or the primary authority cited, use the term “contra.” “But see” may be used to indicate a holding or dictum that is somewhat contrary to, or inconsistent with, the main authority.


  24. locknut

    I just finished a master’s program in which it was necessary to learn this and other such annoying, non-intuitive Latin abbreviations I had to look up each time I used. I found you when searching whether cf. was meant to compare only, or contrast only. Thanks for clearing that up.

    I had no idea about counterfeit! I think there are many such words that had meanings opposite to how they’re used today. This is one reason it’s so difficult to read books written 100 or more years ago. I’d understood moot point as irrelevant to the topic, not something up for debate. Interesting. Beg to differ sends me into a tailspin ever since I learned the real meaning.

    It’s also interesting that you advocate for retreating from using a word for its ambiguity during a shift in meaning, like, until the dust settles. Why not rather FIGHT to include and defend the correct meaning as much as possible? (Ha ha. Seems like redundant/overkill, but you could even footnote your usage to clarify what/which version you mean.)

    Alas, it seems the abandonment of Latin education has only helped to “seal us off” from much scholarship (and especially from the enjoyment and comprehension of old books, in which authors throw Latin around as if very common to their audiences!).

    Thank you for the list of other abbreviations at the end. I will be returning here!



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