DailyWritingTips

CamelCase

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A reader commenting on my e-mail post brought my attention to a term I’d not heard before:

It will end up simply as book, but before that happens it will be ebook—just as email ended up as email. eBook looks entirely too corporate to me, and I doubt if the general writing public will ever adopt camel case for anyThing, ever.

Camel case, also appropriately spelled CamelCase, is the practice of writing a word with a capital inside it. For example:

iPhone
CinemaScope
VistaVision
AstroTurf

The name comes from the fact that the uppercase letter makes a “hump” in the word.

The Wiki article gives a long list of other terms for this practice. Here are a few: BumpyCaps, CamelBack, CamelCaps, CapWords, mixedCase, and RollerCoasterCaps.

I have to agree that words written that way are a bit too cutesy to survive as real words.

That’s not to say there is no practical use for the mingling of upper- and lowercase letters. For example, in chemistry: NaCl, AgF, BaSe, etc.

As for the e-book poll, 326 DWT readers voted. The form e-book received 50% of the votes. The CamelCase version eBook came in second at 26%.

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12 thoughts on “CamelCase”

  1. Camel case is invaluable and often required by convention in programming. Elsewhere it smacks of marketese as you say.

  2. In addition to programming, in places where spaces, hyphens or underscores are not allowed, there are file names, again where spaces, hyphens or underscores are not allowed.

    And CamelCase can help with legibility with domain names. One might use a URL like and get predictably stable and expected results. Note you *cannot* change case of letters after the single-slash. (vinculum?) since many hosts are Unix or Linux based, and filenames and folder names are case-sensitive.

  3. From the pregrammer’s point of view, “iPhone” is the only example of Camel case. “CinemaScope”, “VistaVision”, and “AstroTurf” represent the so-called Pascal case. The difference between the two is the case of the first letter: in Camel case, it’s lower, while in Pascal case, it’s upper. For more info, see: 28VS.71%29.aspx.

  4. In some programming circles camelCase is differentiated from PascalCase (also known as UpperCamelCase). In regular camelCase, the first letter is not capitalized.

  5. Note you *cannot* change case of letters after the single-slash. (vinculum?) since many hosts are Unix or Linux based, and filenames and folder names are case-sensitive.

    That really isn’t relevant, since URLs are not filenames…they’re specified as case-sensitive, so officially you can’t change case even on OSes that canonicalize or ignore case, but since mapping them into pathnames is so common you might be able to get away with it on some servers (I’ve never thought to try…but what do Windows web servers do with URLs containing characters that are not legal in pathnames? There are no such characters on Unix (except for slash and NUL, which can’t occur in an URL component anyway), so the mapping is trivial there)

  6. Peter,

    The domain name is case insensitive. Mix capitals and lower case letters to your heart’s content – between the http[s]:// and the first following /.

    The domain name is never used directly to access a file on a host computer. Instead, the browser sends the domain part to a Domain Name Server (DNS), to be translated to an IP (Internet Protocol) address – such as 70.254.231.87, for instance. The IP address uniquely identifies one single resource attached to the internet. Then your browser accesses the host using the IP address and the remainder of the URL; the host that gets the request treats the remainder of the URL as a filename under the hosted part of it’s operating system.

    The Domain Name Server processes the name in a case-insensitive manner. That is why the domain name part of the URL is case insensitive (including CamelCase, or Pascal case, as Microsoft would have it, when the initial letter is upper case), and the following part is usually case sensitive.

    A URL after the domain and ‘/’ is host-dependent. The common approach across all servers I know about today is to use actual (legal!) file system filenames and directory (folder) names as literals in the URL, evaluating to an actual filename at some point. If your host is windows based, Index.html and index.html will likely both pull up the same page. On Linux or Unix, it will not – the difference between ‘I’ and ‘i’ character in Unix or Linux is exactly the same difference as between ‘-‘ and ‘_’ – they are different characters in every aspect, at least as used for file names, directory names, and URL’s.

    The part of the URL might still contain upper case letters, but they should be treated as non-discretionary. If you change the case of the letters in the latter part of the URL, you will likely void the URL and fail to find a valid page.

  7. I used to work for a newspaper called MiD DAY. Now, does that qualify as a CamelCase word? Or is there a word that describes CamelCase in inverse?

  8. The domain name is case insensitive.

    Yes, I know that. That’s also specified in the relevant standard.

    Then your browser accesses the host using the IP address and the remainder of the URL; the host that gets the request treats the remainder of the URL as a filename under the hosted part of it’s operating system.

    No it doesn’t. That is, it may well do that, most of the time, in practice, but that’s not what it’s doing in theory: an URL is simply a resource identifier; what the resource “means”, whether it represents a file (and, if so, how the file path is related to the URL string), an entry in a database, or whatever else you can think of, is up to its handler. FWIW, URL components can have associated data that can’t be mapped into the filesystem; e.g., something like http: //foo.com/xyz;abc=def,ghi=jkl/uvw;m=n — the “path” components are “xyz” and “uvw”; “abc”/”def” and “ghi”/”jkl” are non-path elements associated with the “xyz” component, etc.; it wouldn’t be legal to map it to a file named “uvw;m=n”, if you supported that URL.

  9. This is interesting, especially after perusing Wikipedia’s list of examples. It occurs to me that I’m entirely inconsistent about CamelCase in formal or academic writing.

    For example, I’m rather sure I always use AmeriCorps, but would usually type Powerpoint or Power Point.

    I’d always cite ProQuest, but never HarperCollins, which is always Harper Collins.

    Part of this is ignorance on my part (it’s SpongeBob SquarePants, not Spongebob Squarepants? Who knew?) but also a bit of an aesthetic or political choice when a “CamelCase” looks displeasing or stinks of corporate manipulation (there’s no way I’m switching to RadioShack.)

  10. @ Peter,

    Oops. My bad. As soon as I hit “Submit Comment” I remembered about using the URL for passing tokens, invoking scripts and applications (“apps” for the web 2.0 generation).

  11. “just as email ended up as email.” – You mean:

    “just as eMail ended up as email.”-right?

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