It might be a useful feature to be able to underline different English words on english.stackexchange

screen capture of what the \underline feature does in website which have the mathjax plugin

The text underlining shown above was done using the MathJax plug-in.

There are more than 40 existing websites in the stack exchange family which already use the MathJax plug-in.

I would never require anyone posting a question or answer on english stackexchange to use MathJax syntax inside of their posting.

However, I think underlining and coloring text is useful would be useful for some.

The source code for the example where "swam" was underlined is shown below:

They $\underline{swam}$ across the river.  

In order to underline the verb "swam" you would simply write $\underline{swam}$ inside of your question or answer.

Nobody posting a question or answer to english stackexchange would be required to write strange things such as $\underline{swam}$.

MathJax formatting would be available for those who choose to use it.

Everyone else could use plain English.

Underlining and color-coding text could be done by experienced moderators and other users who want to underline text or highlight different words in different colors.

Note that we can also use the MathJax web plugin to apply color-highlighting features to the English branch of stack exchange:

screen capture of some text colored maroon and olive-green

Inside of a question or answer, a person would write:

$\color{maroon}{\text{these words are maroon}} $ 
$\color{olive}{\text{this text is olive-colored}}$  

A user could optionally choose to show all of the verbs in blue, nouns in maroon, adjectives in olive-green, etc...

It is useful sometimes, but not always.

You can also strike-out passages of text using MathJax

screen capture of stricken text rendered with mathjax


They $\cancel{is}$ [are] going to the park

a screen capture of the word "is" being stricken and replaced with a blue instance of the word "are"

$ \require{cancel} $

$ \require{enclose} $

$ \newcommand{\strike}[1]{\color{grey}{\enclose{horizontalstrike, updiagonalstrike}{#1}}}$


$\newcommand{\replace}[2]{\strike{#1} \insert{#2}}$  

> They $\strike{is}$ going to the park. 
> They $\insert{are}$ going to the park. 
> They $\replace{is}{are}$ going to the park. 

3 Answers 3


If we could agree on how we, as a site, would use the various markup flavors, this might be an interesting idea. But I doubt that we would or could do that. With the minimal markup we have now, people do different things in different ways, with little consensus. Multiply the possibilities and I think all we would achieve is chaos.

  • The other sites that have implemented MathJax have not had any of the problems you have mentioned.
    – Mitch
    Commented Sep 26, 2022 at 15:09
  • @Mitch: All this should be in the service of making communication clearer, not more capricious. Just my opinion.
    – Robusto
    Commented Sep 26, 2022 at 18:41
  • Sure, and the OP is trying to make their posts clearer by using these features. The single feature of 'underline' is bad (because of what tchrist said, it's already used for hyperlinks. The feature of colors... he just wants to highlight differently no big deal not some rainbow vomit example. The chaos you see is entirely personal variations on how to emphasize (indentation, bolding, etc)... adding a tool for color will only be for the vanishingly small set who know LaTeX and they might be expected to format -better- since they care.
    – Mitch
    Commented Sep 26, 2022 at 20:49
  • 1
    Anyway, for the handful of times I've wanted to do math here, really it's not necessary.
    – Mitch
    Commented Sep 26, 2022 at 20:49
  • 2
    We don't agree on how we use the other things we can do here. Why would we agree on underlining, strikethrough, et al? Commented Sep 26, 2022 at 21:58
  • 1
    @JohnLawler: My point exactly.
    – Robusto
    Commented Sep 26, 2022 at 23:49
  • @JohnLawler What is the issue with different approaches if each approach is clear and obvious? If someone writes so unclearly that their highlighting would need to be done in accordance with a pre-established syntax, then they're already problematic for the site. More highlighting options isn't going to make their influence worse. The people that are already clear however, will only be able to increase their clarity through their potentially idiosyncratic, yet nonetheless clear, use of highlighting. This feature would only help the good communicators, yet not worsen the bad ones.
    – user110391
    Commented Oct 3, 2022 at 11:08

First off, pretty, pretty please go read this short piece about page color and colored text.

When you get back, here are a few choice reasons against this proposal:

Ransom note text reading: It would be incredibly distracting, not to mention confusing and discriminatory, to have colorized texts with nonlinking underlines and non-struck-out strike-outs.

  1. The main problem with this idea would be its potential for looking 𝕘𝕒𝕦𝕕𝕪 and 𝒸𝓇𝒶𝓈𝓈 compared with our existing page setup. We’ve gone for a quiet look here, in keeping with our theme. It’s supposed to bring to mind a book, not a noisily <BLINK>ing popup spamvertizing billboard</BLINK> on Times Square trying to get you to run go see the next Broadway production of ♬ Joseph and the Amazing Technicolor Dreamcoat ♬ — and right this very minute❢❣❣ Basically, it’s way too easily abused for chintzy purposes related to grabbing people’s attention against their wishes.

  2. You’re also going to run afoul of any number of important WC3 accessibility guidelines relating to contrast as well as impacting use by screenreaders. We do not want to make our site less accessible. How would the colors interact with our theme colors? What happens to people who have various deficiencies in their color vision?

  3. There is a non-trivial performance impact involved with enabling MathJax on an SE site. Making everyone pay that price just so certain wizards could bedazzle us by casting a Prismatic Spray spell might not be a price that our community is willing to pay.

  4. It would have to pass muster and be approved by the Stack Exchange Community and Design teams. We can’t even get the SE design team to exchange our super-double-bold markdown that destroys our page color for elegant small capitals that preserves it the way things should be, or get them to disable the hideous code markdown possibility that should not even exist here. So I wouldn’t guess this proposal’s reasoning and impact would pass their internal smell test—and it would have to do so to be allowed—but hey you never know.

  5. The reason we don’t have underlines in our markdown is because we already use underlines for something else. If you also add them  ̲t̲o̲ ̲y̲o̲u̲r̲ ̲s̲w̲a̲m̲ ̲e̲x̲a̲m̲p̲l̲e̲ ̲, it just risks confusing people.

  6. And finally, the reason we don’t have strike-outs oh never mind, I guess we do. :)

Opinions will doubtless vary according to each community member’s personal preferences and tolerances for various sorts of in-your-face loudness.

For a host of diverse reasons, some good and others rather less than good, virtually no previous change to our UI here has ever been well-received by our community. And there have been painfully many of those; nobody is ever happy with them. So for my own part I would be astonished if, on balance, our community at large here were to end up considering this proposal more of a positive change than a negative one.

But we shall see — for as that old apocryphal proverb runs: “By their votes shall ye know them.”

  • 1
    The other sites that have implemented MathJax have not had any of the problems you have mentioned.
    – Mitch
    Commented Sep 26, 2022 at 15:09
  • 2
    @Mitch They are not using it for colorizing normal text against a colored background, now are they? And yes, the page load times definitely suffer. We use colored underlined text for links here. It would be confusing to have colored and/or underlined text that were not actually a hyperlink.
    – tchrist Mod
    Commented Sep 26, 2022 at 15:27
  • Is #2 a rhetorical question? When I use my screen reader (VoiceOver) on the last example I hear this: "They | eye ess are (double tap to open math in full screen) | going to the park" where "|" is a break and the part in parens is a hint, though double tap does nothing. In other words: I cannot tell the difference between regular text, strike through text, and colored text when using it.
    – Laurel Mod
    Commented Sep 26, 2022 at 18:03
  • 1
    @Mitch I checked out some math in VoiceOver and it is fairly accessible with the right screen reader settings. For example, for a fraction it will say: "fraction start numerator over denominator fraction end". (It still gives me the nonsensical hint about double tapping however.) How accessible MathJax is depends on what parts of it are being used, and I suspect that if you're using the math parts how they should be used it's fine.
    – Laurel Mod
    Commented Sep 26, 2022 at 18:33
  • @tchrist There are two things the user is asking for, 1) a way to do those things (colors, underlining, etc) and 2) MathJax. I agree that to do those things using MathJax to get things that are already part of markdown would be silly and counterproductive. But colors in general is a reasonable thing to ask for (and if it is abused is easily closed/commented/downvoted). I'm just saying that whatever the reasons for or against MJ, these reasons seem secondary.
    – Mitch
    Commented Sep 26, 2022 at 19:58
  • 1
    I didn't realize but there is a good set of posts on SE about color and underlying and such that bascially say 'No, don't do either of those'. MathJax is great for math but should not be used to bypass those recommendations.
    – Mitch
    Commented Sep 27, 2022 at 15:48
  • I think your second point could use a little more emphasis. A prevalence of MathJax on this site would represent a complete loss of functionality for screen readers. Commented Oct 11, 2022 at 20:06

Please please please please please enable MathJax.

Any issues with bots and screen readers are 0% our concern and 100% a challenge for the developers of those technologies. I've worked with the disabled for 40 years, and censoring the able bodied in any way is not the way forward with regards to helping our community.

This site is fundamentally elitist in nature. We strive to maintain a veneer of egalitarianism, sometimes sadly, sometimes comically, and sometimes with conspicuous hypocrisy - this is one of those times.

"The principle [of censorship] is wrong. It's like demanding that grown men live on skim milk because the baby can't have steak." Robert Heinlein.

I took the trouble to figure out what a screen reader was, installed one, got MathJax's accessibility feature sorted, and tested it on a page from Engineering SE. It works. It's not the most fluent rendition of math that I have ever heard, but it works. So that objection simply doesn't hold water. And I expect the formulas that would appear here would be less of a challenge to render aurally.

Why would a feature such as MathJax be acceptable for one site on SE and objectionable for accessibility reasons on another? We do, in fact, have a tag, and currently, the only way to include readable math formatting is with a screen grab. And we get a decent number of questions about the text that gets interleaved with math in documents.

The issue is also not about the potential for the tool to be misused or used in a clumsy way. It is about whether it can make things better when used adeptly.

  • It sounds like you're talking about another use of MathJax entirely (equations), which is both its intended use and also works well with screen readers in my (also limited) experience. (Strikethrough and coloring, the MathJax in the question, don't work with screen readers.) I think this is different enough that you should ask a new question, including examples of posts that would need formatting to make a case. (There needs to be enough posts that would benefit to outweigh the cost of loading another thing on every single page.)
    – Laurel Mod
    Commented Oct 27, 2022 at 15:28

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