Does using numerous   whitespace characters to center a line of text cause accessibility issues?

Question

I'm quoting something that has a centered line of text in the source formatting (pg. 175 of the D&D 5e PHB). I initially used the MathJax display style environment $$ like so:

Here’s how to determine a character’s total for a passive check:

$$10 + \text{all modifiers that normally apply to the check}$$

If the character has advantage on the check, add 5. For disadvantage, subtract 5.

>Here’s how to determine a character’s total for a passive check:
>
>$$10 + \text{all modifiers that normally apply to the check}$$
>
>If the character has advantage on the check, add 5. For disadvantage, subtract 5.

However, we generally prefer to avoid MathJax unless it is necessary (like the post contains math) since not all devices support it. So instead I've used the   character to approximately center the line:

Here’s how to determine a character’s total for a passive check:

                         10 + all modifiers that normally apply to the check

If the character has advantage on the check, add 5. For disadvantage, subtract 5.

>Here’s how to determine a character’s total for a passive check:
>
>                         10 + all modifiers that normally apply to the check
>
>If the character has advantage on the check, add 5. For disadvantage, subtract 5.

So while the markdown looks ridiculous, the output nicely matches the source formatting without using MathJax. Is this a better solution than using MathJax to center the line? Are there any accessibility related reasons I should avoid doing this as well?

Answer 1

Irrespective of accessibility, it just isn't a good solution in general.

Checked my own post on my phone, and using   doesn't work; it was aligned in the desktop browser I was using, but is going to be a crap shoot in other browsers and devices:

I guess there just isn’t a good way to center align text that isn’t MathJax.

Answer 2

Unless formatting is important, don't quote formatting

A general rule in quoting is, that formatting is not taken from a text unless it is important. Importance is usually only afforded to properties in the fontset, such as italics, bolding or CAPITAL LETTERS.

Text formatting on the page is usually not deemed essential in qupting, so a quote usually does not care for indentation or center format. The only exception in this is linebreaks, which often are deemed essential, and in some quotations are remarked with // or a similar orthographic solution in case the quote can't contain actual linebreaks.

Center-alignment

MathJax

But if you absolutely must have center format, MathJax allows text with $$\text{center}$$ for $$\text{center}$$

However, MathJax isn't always playing nice with screen readers, and such should be avoided for formatting only.

HTML doesn't work anymore

At some point, basic HTML was disabled from StackExchange, so that <p align="center">test</p>, usually a center-aligned text, is now rendered as follows:

test

In fact, the relevant HTML code isn't visible in the dev-console F12, and likewise the more verbose <p style="text-align:center;">test</p> wouldn't get parsed as formatting but stripped, just like <div align="center">test</div>:

Answer 3

This is zero issue for screenreaders

A screenreader will just treat all those spaces as a space and move to the next text it has to read aloud, so it won’t cause any problems for those who rely on them.

Centering text is probably not an accessibility problem

Ignoring (for the moment) the “bug” you found, this is effectively centering. I have never received guidance that centered text is a problem for accessibility, and I have worked a fair amount on accessibility under the direction of accessibility experts (to wit: I would not claim to be one, myself). Accessibility is vast, and frankly it’s not a monolithic agreed-upon thing: there are a lot of suggestions, sometimes contradictory, about many details, once you get beyond the low-hanging fruit of headings, contrast, alt properties, and so on. But the general fact that most people find centering a useful way of “centering” some text is probably a good sign: it may very well improve accessibility, done well.

But of course, this isn’t actually centering the text

As you point out, narrower viewports cause text that is “centered” in this way to look awful, since the line wraps and the “centering” turns into what it actually is: an indent. Worse, this isn’t limited to narrow viewports: different fonts, different font sizes, etc. etc. If someone doesn’t have the Georgia font installed on their system, they’re going to see a different font, and that font’s relative widths will (probably) be different. If Stack Exchange decides to change the font in use—as they have in the past—then everyone’s “centering” will be off.

These problems aren’t really resolvable. Unless Stack Exchange offers proper centering, we don’t have it.