Re: Tags inside themselves??

Murray Maloney (murray@sco.COM)
Mon, 12 Sep 94 14:14:20 EDT

My $0.02 is interspersed below...
> 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?

Yes, of course blockquotes should be nestable. Rendering is left
as an exercise for the browser implementor :-)

Seriously though. It is perfectly normal to expect that a quote
would include a quote. Certainly this is no less true of block-quotes.
Rendering of block quotes could follow the following rules (or not):

- initial block quote is indented by 2-5 spaces,
possibly right-indented by 2-5 spaces,
possibly delimited by double quotes,
and possibly rendered in a distinguishing typeface

- first nested block quote is indented an additional 2-5 spaces,
possibly right-indented by 2-5 spaces,
possibly delimited by single open and close quotes,
and possibly rendered in a distinguishing typeface

- subsequent nested block quotes indented additional 2-5 spaces,
possibly delimited by alternating double and single quotes,
and possibly rendered in a distinguishing typeface
> 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.

That Mosaic does not distinguish them does not make them invalid.
Nested block quotes are definitely a valid construct that are,
unfortunately, not specifically distinguished by Mosaic.
> >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
> >viewers/processors.
> 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>

Yes, this is what I recall that we agreed upon.
I will also note that it is not incorrect to render
the first example with a bold-italic typeface for the word "bold".
> 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!?!?)

Very good point. If a nested block quote were rendered in italic,
and <I> were encountered within the quote, then one might expect
the emphasized phrase to be rendered in roman or bold. What's most
important is that the intention of the author to emphasize the text
must be preserved, not simply the specific emphasis indicated by the
markup used.
> Dan