Re: Tags inside themselves??

Daniel W. Connolly (
Mon, 12 Sep 94 01:15:07 EDT

In message <>, Stan Newton writes:
>The following message body is a retransmission of an earlier message to
>, from which I received no reply:

By the way... I suspect an administrative problem. I subscribe to
www-html, and I think I would have rememberd seeing comments like
this if they had made it to my mailbox.

>The HTML DTD Reference (Level 2) states that BLOCKQUOTE tags are allowed in
>BLOCKQUOTE tags (pg 6-2) but nesting of BLOCKQUOTEs and possible rendering
>is not discussed. The HTML DTD (pg 5-5 & 5-7) defines BLOCKQUOTE as a member
>of the %block Entity and defines the BLOCKQUOTE Element to contain
>%body.content which includes %block. Is this intentional? Can I have
>Blockquotes inside Blockquotes, that is, can Blockquotes be nested?

Dave Raggett also asked about this...

At the time I drafted the DTD, I got this idea that it would be neat
to be able to select a range of text in one browser, and paste it into
an editor, which would mark it up like:

...selected text...
<address>author/url of selected text</address>

If blockquotes aren't allowed inside blockquotes, this is not possible
in general.

My little fantasies aside, Mosaic (nor any other browser I know) does
not distinguish nested blockquotes from non-nested blockquotes. So
perhaps blockquote-inside-blockquote should be postponed to a later
version of the spec.

>The HTML DTD Reference (Level 2) states for each of the Highlighting tags
>(B, CITE, etc.) that the tags are allowed inside of themselves. See, for
>example, Bold (pg 6-2). The HTML Level 1 DTD (pg 5-10) defines allowable
>content for %font and %phrase elements in terms of a %phrase.content entity
>definition which includes the %font and %phrase entity definitions, thereby
>placing the tags inside themselves.
>Shouldn't each of the Highlighting tags be allowed to include all
>Highlighting tags EXCEPT ITSELF? Since the Highlighting for any specific tag
>should already be on, the appearance of another tag with the same
>Highlighting does nothing and has the potential to confuse some

The issue of nested Highlighting elements was discussed in Toronto.
I'm not sure if anybody wrote up the results anywhere...

I believe the consensus was that nested highlighting markup was
not an error, but a browser was not required to distinguish
nested markup from non-nested markup. i.e. a conforming implementation
may render the following two cases identically:

<i>italic with <b>bold</b></i>
<i>italic with </i><b>bold</b>

Not that it's necessarily relevant, but as an example, in TeX markup,
it is quite common to see {\em title with nested {\em emphasis}}.
It is also conforming to render:

<em>title with nested <em>emphasis</em></em>
just like:
<i>title with nested </i>emphasis
(hmmm... there's no "plain" or "roman" tag!?!?)