W3C home > Mailing lists > Public > www-validator@w3.org > May 2013

Re: [VE][html5] Add Subject Here Getting an error for using Unicode PUAs!

From: Jukka K. Korpela <jkorpela@cs.tut.fi>
Date: Fri, 03 May 2013 20:41:41 +0300
Message-ID: <5183F6D5.8060702@cs.tut.fi>
To: Anon SU <anonymous84327@gmail.com>
CC: www-validator@w3.org
2013-05-03 20:13, Anon SU wrote:

> The use of PUA is optional in IcoMoon, as according to their documentation:
>     /Using Latin letters is not recommended for icons fonts. *Using the
>     Private Use Area of Unicode is the best option for icon fonts.  By
>     using PUA characters, your icon font will be compatible with screen
>     readers. But if you use Latin characters, the screen reader might
>     read the single meaning less letters, which would be confusing./

That's trickery upon trickery: They use data-icon and CSS generated 
content to add a character in the rendered content and CSS settings to 
render that character as an icon that has nothing to do with the 
character. And when they realize that some browsers might actually read 
the character as what it is (as opposite to what they try to display 
instead), they then change e.g. a Latin letter to a Private Use 
character. So what happens when some browser makes a real effort at 
displaying or speaking the Private Use character? Uttering “Private Use 
character U+E000” would be a reasonable move, and would make the page 
look foolish.

> Is it a wrong usage?

It is very, very wrong, especially since they clearly offer their 
techniques for use on WWW pages. But this is a matter of principle 
rather than a serious practical issue. (The main practical problem with 
icon fonts is that they so easily lead to excessive use of icons, often 
ugly icons.)

> if so, what would you suggest as an alternative?

Icons are not characters, as a rule. They are images, and should be 
presented in HTML using <img> tags.

> I have customers asking me why their website gets a warning by the W3C
> Validator, what should I tell them? that the Validator is wrong?

A warning is seldom "wrong"; it can be useful, or useless, or sometimes 
misleading. Here it is useful, even though it is not based in HTML5 or 
Living HTML. Private Use characters *can* be used in HTML, but they 
*should not* be used as a rule, and this applies particularly strongly 
to open information interchange (as opposite to use in a standalone HTML 
application for example).

On the other hand, the real impact of icon font trickery is relatively 

On the formal side, this is not a conformance issue, and HTML5 
validation in general means informal and experimental checking against a 
mutable definition.

Received on Friday, 3 May 2013 17:42:09 UTC

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