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Proposal: Remove W21 "Byte-Order Mark found in UTF-8 File"

From: Takeshi Kurosawa <taken.spc@gmail.com>
Date: Mon, 30 Mar 2015 22:12:52 +0900
Message-ID: <CAHL3uyOYXriVpJx6rUP8fgc_SryaPKWD5HHRsOPsSF=E+9ucRw@mail.gmail.com>
To: www-validator@w3.org
Hi all,

I would like to propose removing W21 "Byte-Order Mark found in UTF-8
File" warning from the W3C Markup Validator.

W21 "Byte-Order Mark found in UTF-8 File"
> The Unicode Byte-Order Mark (BOM) in UTF-8 encoded files is known to
> cause problems for some text editors and older browsers. You may want
> to consider avoiding its use until it is better supported.


1. The validity of a document is not related to the BOM

The previous warning message of the W3C Markup Validator stated that a
document with BOM is "perfectly valid"

2. HTML5 requires User Agents recognize BOM

I understand that the W3C Markup Validator doesn't support HTML5
directly. However I would like to saythe  the situation described in
the message was changed. As far as I know, the major browsers support

"The byte-order mark (BOM) in HTML" doesn't mention any browsers' issues.
# "HTTP precedence" is not an issue I am disusing here. I am
discussing whether the browsers supports BOM or not.

We don't need to say that the BOM is known to cause problems.


A. Remove W21 from the W3C Markup Validator.

B. If A is not possible, bypass W21 check for HTML5 documents as HTML5
requires that User Agents recognize the BOM



Takeshi Kurosawa <taken.spc@gmail.com>
Received on Monday, 30 March 2015 13:13:19 UTC

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