case sensitivity in tags?

Dan Connolly (connolly@w3.org)
Tue, 9 May 95 14:20:48 EDT

Tim Pierce writes:
> Hi, Dan,
>
> I'm hesitant to ask this of html-wg because I'm such a rank
> neophyte, and I don't know how well the issue has been
> covered already.

Hmmm... this is somewhat novel, so I hope you don't mind me copying
the list...

> Is there an official consensus on case sensitivity for tags,
> attributes, and values? I see that the current(?) draft of
> HTML 2.0 explicitly says that names are case-insensitive,

Not exactly. It says:

"Names"
http://www.w3.org/hypertext/WWW/MarkUp/html-spec/html-spec_2.html#SEC11

| ... Element names are not case sensitive, but entity names are. For
| example, `<BLOCKQUOTE>', `<BlockQuote>', and `<blockquote>' are
| equivalent, whereas `&amp;' is different from `&AMP;'.

> but nothing seems to be said about attributes or values, and
> different browsers may implement vastly different results
> for seemingly-innocuous changes in the source.

Some attribute values are case sensitive (the ones typed CDATA
in the DTD) and some are not (those typed NAME or INPUT or enumerated):

ALT CDATA #IMPLIED
vs.
ALIGN (top|middle|bottom) #IMPLIED
ISMAP (ISMAP) #IMPLIED

> For example,
> in the TYPE attribute for the INPUT tag, NCSA Mosaic 2.4
> accepts only lowercase words (so far as I can tell), so tags
> like "<INPUT TYPE=RADIO>" are treated as having an unknown
> type.

That's a bug.

> As far as I can tell, this sort of situation is not
> covered in the drafts, and hasn't been addressed on html-wg.

That bug came up one time, but you're right: I should add a
note in the spec. When I get around to a detailed review of
the forms section, could you remind me?

> Obviously some values should be case-sensitive -- for
> example, values of the HREF attribute. But it doesn't seem
> to make sense to require case-sensitivity of many of these
> others.

> Is this an SGML problem?

Yes.

> Is it something that can be
> addressed with authority? I'll be happy to submit some
> suggested changes to the 3/31 draft,

Please do.

> or bring the issue up
> on the mailing list if you think it would makes sense.

I hope you don't mind I went ahead and did this.

Dan