Re: HTML 4.0/SGML, (#PCDATA)* problem in TEXTAREA

Arnoud (
Wed, 30 Jul 1997 22:09:11 +0200

From: (Arnoud "Galactus" Engelfriet)
Subject: Re: HTML 4.0/SGML, (#PCDATA)* problem in TEXTAREA
Date: Wed, 30 Jul 1997 22:09:11 +0200
Message-ID: <>

In article <>,
"Neil St.Laurent" <> wrote:
> What is HTML's position on handling unknown tags though?  According 

Section 4.2.1 of RFC 1866 (HTML 2.0 spec) recommends that start-
and end-tags for unknown elements should be "mapped to nothing"
(standardese for "ignored") during tokenization.

> to SGML they should simply cause the document to be invalid, but it 
> appears (and I remember reading) that HTML browsers are to simply 
> pretend as though the unknown tag wasn't there.

"Information providers are warned that this convention is not binding:
unspecified behavior may result, as such markup does not conform to
this specification."

In other words, it's common practice to do so, but a browser which
made David Siegel fly out of your nose upon encountering an element
that it doesn't recognize is not violating RFC 1866.

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