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I typically use 

\textit{Some italicized text}

while some of my colleagues use 

{\it Some other text}

Should I bother changing one or the other, or does it matter?

Related:

Is there any reason not to use \let to redefine a deprecated control sequence to the currently recommended one?

Community
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KeithB
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5 Answers5

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From l2tabu:

Why not use obsolete commands? Obsolete commands do not support LaTeX2e's new font selection scheme, or NFSS. {\bf foo}, for example, resets all font attributes which had been set earlier before it prints foo in bold face. This is why you cannot simply define a bold-italics style by {\it \bf Test} only. (This definition will produce: Test.) On the other hand, the new commands \textbf{\textit{Test}} will behave as expected producing: Test.

Apart from that, with the former commands there is no ‘italic correction’, cf. for instance halfhearted ({\it half}hearted) to halfhearted (\textit{half}hearted).

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percusse
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Caramdir
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    To be fair, it's not really that hard to write {\it half\/}hearted. This is how it would be done in TeX, after all. – TH. Aug 29 '10 at 02:27
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    It should be noted that when the blockquote talks about “obsolete”, it means obsolete in >= LaTeX2e. Those commands are not obsolete in Plain-tex or ConTeXt. – morbusg Jul 29 '11 at 04:28
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    (I'm not sure, if there commands existed 2010, but) what about {\bfseries textOne {\itshape textTwo}}? Are they outdated too? What are they for? {\itshape half}hearted doesn't work nice. – user1 Sep 03 '17 at 20:42
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    @Ben They the corresponding "switching" commands and stack correctly (i.e. \itshape\bfseries produces the correct output). Useful for some layout definitions (e.g. in KOMA or titlesec). – Caramdir Sep 11 '17 at 18:43
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Hmm, I just posted this as an answer to another question, but just as I was posting, that question was closed—with a referral here. So I'll throw in my 2¢ here...

The reason I don't like \it and \bf is that they do not play well together. That is, they do not nest as one would intuitively expect:

Whereas \textit and \textbf do play well together:

This is nice. However, you may notice that it still fails to handle nested style adjustments to small caps, since the Computer Modern fonts do not contain slanted or bold small caps:

If this is a problem for you, then what I recommend—and I just happened to learn about this yesterday myself—is the wonderful slantsc package in combination with the lmodern package. slantsc provides, among other things, \rmfamily (roman), \ttfamily (typewriter/​teletype), \sffamily (sans-serif), \bfseries (boldface), \itshape (italics), \slshape (slant/​oblique), and \scshape (small caps). With these, small caps can obtained in slanted form:

As a bonus, slantsc fixes \textsl to behave properly with \textsc, so you can continue using those if you like.

Alas, I haven't yet found a package which fixes the behavior of nested instances of \textit. In typesetting, when you nest italics, you're supposed to come back out of italics to roman. For example, the word "Titanic" below is in nested italics:

Tanaka, Shelly. On Board the Titanic: What It Was Like When the Great Liner Sank. New York, NY: Hyperion/​Madison Press, 1998.

As a workaround, you can usually write \textrm to temporarily return to non-italics in those cases, but of course this is only valid if you know the exact number of nested italic levels, which may not always be the case, especially inside a macro.

Update:

As others have pointed out, \textit and \textsl do automatic italic correction, whereas \it, \itshape, \sl, and \slshape do not. Thus, you can write \textit{stuff}, but you must write {\it stuff\/} or {\itshape stuff\/} to get the same effect.

Todd Lehman
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    I would not expect \textit (or any other command intended to do italics) to generate non-italic text. On the other hand I'd expect \emph (which is used to emphasize) to switch to italics if not already in italic mode while to switch off italics when in italic mode (because emphasizing is usually done this way). And guess what, that's exactly what \emph does. The correct way to type the title above therefore is: On Board the \emph{Titanic:} What It Was Like When the Great Liner Sank. Note that Titanic is emphasized, not italicised. – celtschk Jan 20 '12 at 19:42
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    @celtschk: Cool, I did not know that! (Or I think I did once long ago and forgot!) Thanks so much for pointing this out. – Todd Lehman Jan 23 '12 at 17:03
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    Note that cfr-lm will give you access to the same features but uses slightly different commands. cfr-lm relies on virtual fonts but also makes other features of the LM family available (e.g. different styles of figures, different weights etc.). Disclaimer: I wrote cfr-lm. – cfr Dec 17 '13 at 23:46
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    @celtschk, ‘Titanic’ is not set in italics because it’s emphasized, but because its a custom of English typography to italicize names of vessels, like (family) names are set in small caps elsewhere. Therefore using \emph would be inappropriate. – Crissov Jan 29 '14 at 10:30
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    Note that Latin Modern also features an upright italic font. – cfr Apr 27 '15 at 02:47
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The \it syntax is inherited from LaTeX 2.09, and is regarded as supported 'for historical reasons only' in LaTeX2e. For bold, you should go for \textbf rather than \bf. For italic, you'd usually use \emph rather than \textit as it's semantic mark up and as it handles the italic correction automatically.

Joseph Wright
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    I beg to differ. If you want to set italic text, \textit is the way to go. But if you want to emphasize some text, then you should use \emph{}. – qbi Jul 28 '10 at 20:12
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    It's very rare that you want inline italic that isn't in some way semantic. For longer blocks, \itshape is the way to do things, of course. – Joseph Wright Jul 28 '10 at 20:24
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    Of course, semantic markup should always be preferred over syntactic one, but the question was specific about the difference between \textit and \it – Juan A. Navarro Jul 28 '10 at 20:45
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    Or, if you want a command that is used in the same way as \it, use \itshape. – Sharpie Jul 28 '10 at 21:53
  • @qbi and @Joseph I'm sorry, I must be daft. I don't understand the above discussion. I want to know when to use \emph, and when to use \textit. I feel like there is some discussion above that answers my question, but I can't figure it out. Could you either make it more clear, or should I ask this as a separate question? – BBischof Aug 18 '10 at 18:13
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    \emph is semantic: it says 'make things emphasised'. On the other hand, \textit means make this italic. By convention, \emph makes things italic, but you can redefine it to do something else (for example, the beamer class makes text red). On the other hand, \textit is always italic. So it is usually advised to use \emph in a document, using \textit only when you need definitely italic text. This might make a good question, as I'd then have more space to give detail! – Joseph Wright Aug 18 '10 at 18:25
  • @Joseph, Done. :) – BBischof Aug 18 '10 at 18:57
  • @JosephWright Well, you want to use \emph{} when you want to emphasis something. If you need something italic for another reason (Such as convention) then \textit{} (Or a semantic wrapper around \textit{} ) would be better, right? – Canageek Dec 17 '13 at 22:48
  • @Canageek Yes, that's the idea. The reason \emph 'stands out' is I guess it's very common. – Joseph Wright Dec 18 '13 at 06:51
  • \emph does not always mean to italicize. Sometimes it means to un-italicize. Consider the difference between \emph{This is \textit{italic} text} and \emph{This is \emph{italic} text}, particularly when you might not have control over when your text is wrapped or set in italics, like a bibtex title. – cslstr Mar 13 '14 at 11:39
  • If I was writing "foo, bar, etc.", that should be written as foo, bar, \textit{etc}., correct? I am not emphasizing etc, I am italicizing it because it is a foreign language. Even if "emphasizing" is defined to be in red, I still want it in italic. – Troy Daniels Aug 18 '14 at 19:29
  • @TroyDaniels That's a bit complicated because of the italic correction. I guess I'd favour \newcommand*\foreign[1]{\emph{#1}} so you get logical mark-up in the document. – Joseph Wright Aug 18 '14 at 19:38
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    @TroyDaniels But in a block of italic, you'd then want etc. in upright, wouldn't you? (I've never put etc. in any different face myself, so this is entirely hypothetical.) – cfr Apr 27 '15 at 02:44
  • @cfr what do you write instead of etc.? – manooooh Feb 15 '19 at 21:10
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Regarding the deprecated "old font commands", I find them quite useful for equations.

Let's say e.g. that I want to write a symbol for an external potential as $V_{ext}$. However, it is a common convention to use upright characters for subscripts and superscripts that are labels rather than variables, which can be written as either

V_{\mathrm{ext}}   or
V_{\rm ext}

I strongly prefer the latter, as the lower character-count and nesting-level makes reading and editing easier. Though there are cases where the advantage is diminished, e.g. with vector component notations like

f_{\mathrm{ext},i} vs
f_{{\rm ext},i} or
f_{\rm ext\it,i}       % <- not tested

Some modern document classes do not provide the old-style commands anymore. In this case, they can be reintroduced with \DeclareOldFontCommand, see e.g. What exactly does \DeclareOldFontCommand and \DeclareRobustCommand do?.

kdb
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  • Yeah, I think it was a dumb choice to deprecate and move to a command with more characters, why not just redefine \rm with the new functionality, or provide a package that makes pointers such that the better shorter name can be used. – RJ Acuña Feb 17 '22 at 19:18
  • @RicardoAcuna Redefining existing commands can have all sorts of nasty follow-up effects. E.g. a bibliography style may depend on the old style commands and then silently do the wrong thing (which is generally worse than an error message). As for the "more character" commands: I think we got bitten there by a "cleaner, more uniform syntax" (good practice for programming) vs "everyday typesetting usability" trade-off. – kdb Feb 19 '22 at 09:31
  • You forget latex isn’t designed to be a programming language, I know it’s Turing complete. But, the point of latex is every day typesetting. Maintainers treat it as a programming language, that’s stupid. It’s not it’s a typesetting program, so usability trumps uniform syntax. – RJ Acuña Feb 19 '22 at 21:47
  • I mean I guess back-compatibility is important. But instead of deprecating, they could add a versioning package \usepackage{latexv2022} just full of pointers. That way you don’t break back compatibility because the pointers are just local to the Tex file. – RJ Acuña Feb 19 '22 at 21:51
  • Also @kbd we don’t have uniform syntax every time I need to do anything non standard it’s a rabbit hole of packages and macros and the answer is often buried deep in tex.stackexchange and it’s a one off hack. End rant. – RJ Acuña Feb 19 '22 at 21:53
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    @RicardoAcuna I agree there, it is not a programming environment. I just suspect, that treating it as one is what got us the deprecation of \rm and the like. – kdb Feb 19 '22 at 23:01
  • \rm , \it are not deprecated they are simply not defined at all. Some classes (including article) may define compatibility definitions for compatibity with latex2.09 from 1985, but with other classes (including KomaScript classes) you will get errors from the form you "strongly prefer" @RicardoAcuna – David Carlisle Sep 28 '22 at 14:18
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I don't completely agree with Caramdir's answer, since it is true that \it should not be used because it is obsolete, however the corresponding non-depreciated command is \itshape.

So, in your example \it should be replaced with \itshape. However, in some cases as for \textit{half}hearted vs {\itshape half}hearted, the former is preferable.

estownya
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  • Is this a new answer or is it a replication of Caramdir comment or Todd Lehman answer? – Bobyandbob Oct 01 '18 at 16:35
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    @Bobyandbob: It is a new answer since without the comment Caramdir's answer is misleading: it asserts that \it is obsolete since it has no italic correction. Todd Lehman on the other hand points out that \bf and \it don't play well together, however they should be replaced with \bfseries and \itshape (so is not a reason to change to \textbf/\textit)! He also wrongly implies that you need the package slantsc for \itshape and \bfseries, which is not true – estownya Oct 01 '18 at 20:23