Webmaster Forum / HTML, CSS, Scripts / HTML / August 2008

Hello Lars.

Yes and no. It is an interesting thing to ask and I would answer in the
end by saying that some presentation is deeper and captures a reality
better than other presentations. So I take issue with your use of
"just". It can get to the point where presentation makes *all* the
difference! So much so that we can say an ol is really a different beast
to an ul.

uls and ols are not quite like animals that can be captured and
inspected and declared to have this or that. We can try to guess the
intentions of the creators of them. We can stare at the written
technical "standards". Or we can simply understand as best as we can
what would be a reasonable sounding interpretation that made both ul and
ol good and useful. Frankly, I suspect it might have been better for the
world had ols not been borne but we have them and so better think how
best to use them.

One interpretation and use for ols that I favour makes them very
different to styled uls. Sure, you *can* go another way and use an ol
because it gets you some nice numbers for various purposes other than
that the list items have a sequential order that is wanted to be
conveyed. For example:

Aesthetic, it might simply look nice!

Reader usability, it helps to keep track of what item the reader is up
to (not that it *really* matters which item is first) so he doesn't lose
his place when he is suddenly distracted by something... easy to
remember that he was up to item 15... this sort of thing...

There are a million *no-real-ordering* motivations. I guess you might
call these presentational motivations. I am not quite as sure. You might
use an ol to be conveying the count of items, straightforward decimal
numbering will give the number on the last item usually. Useful if you
are shopping and simply have a check if you have missed something. The
number of items bought should at least match the last item number. You
are using and the user is appreciating the ol's facilities here. It
gives a count, is that presentational? Maybe, maybe not.

But I believe there is another thoroughly pure thing that an ol can be
used for. For when you are conveying an ordered set of things, the order
being an important part of the meaning. In this pure role, the ordered
list is an amalgam of two unordered lists, one is the numbers that
represent the order and the other is the ordered items.

Here is a list of three people in order of tallness of three children in
a house:

Tallest: Alice
Neither the tallest nor the shortest: James
Shortest: Matilda

No matter what the order of these lines, the meaning of the results
would be exactly the same.

But if you want to communicate this information in a shorthand and well
known way, you map the three children onto numbers which are known to
grow from smaller to larger. This allows considerable economy of
expression. Don't let the simple example mislead you, there could be a
lot more to keep track of! They might be children of the Chinese state!
We have an unending supply of numbers, and we know how they represent
growing quantity. So we use our ability to generate such numbers to map
big and small and in between...

You might be puzzled when I said that the numbers that represent the
order is an unordered list (if you have got this far reading me <g>). 1,
5, 7, 3 are just numbers and they are what they are no matter what order
we get the numerals in. We would not go:

2. James
1. Alice
3. James

and *explain* that the numbering indicates the order, lowest number is
tallest. But better to let presentation do the talking, and avoid having
to explain so much...

We should explain (for really clear communication), when the numbers are
*not* for the purpose of communicating information abut order! And I
would advise, not use ols unless they are really needed to convey
sequential order.

The tag ol marks things. This tag could alert a browser to do set
things, when it sees an ol, whether there be numerals there or not. It
could have a preprogrammed speech like: "The order is important in the
following list" (It might be too hard for it to know anything more fine
grained than this) or it could insert some text to the same effect,
saving the author. The point I am making is that given we have an ol,
lets use it right. If the order does not matter, use a ul.

Consider that the W3C didn't worry about communicating whether there is
some logic to the ordering of the rows in a table. It's really too
trivial a matter for it to have been dealt with for lists by separate
tags, and I'm surprised it wasn't just an attribute (ordered, or, in
XHTML, ordered="ordered"). Once CSS became mainstream, it seems one of
the tags (ol or ul) could have been deprecated EXCEPT for the fact that
both of them explicitly convey the concept of ordering (ordered in one
case, unordered in the other). It would be awkward, for example, to
deprecate ol and have ul stand in for ordered as well as unordered
lists! A new tag, <list>, could have been invented, but that might have
been too jarring a change.

...

Perhaps it would be interesting to look again at the point of having an
ordered list element in the first place.

What is its point? It is a specialist tag that authors should use to
communicate an ordered list. And, if all browsers were visual browsers,
the whole point of the tag would be completely and utterly lost if in
practice the browser did not generate either the numbers or some other
indication that the user is looking at an ordered list. Another
indication could be the browser has a standard way of inserting a few
introductory words "The order is important..." or some other marker like
a gif. It becomes standard and well known.

In other words, leaving off the numbers and the browser making *no
practical use of the tag* beyond displaying like a ul is only acceptable
as reasonable if other browsers, say aural ones, or aural facilities
make use of the ol tag to convey the idea of the meaning. It is an
accessibility device. It is good practice. If *no* browser used the ol
tag to override instructions by the author about accompanying
indications of order (numbers, voiced words about order...) then the ol
tag would be a totally useless one, it would have no meaning that
differed in practice from a ul. The intentions of authors do not imbue
meaning. Meaning is bestowed by practice. Leaving out numbers etc
undermines the practice or, if you like, depends on most other authors
*not* leaving them out or browsers *not* erasing all traces of ordering
presentation.

Lars was wondering about presentation being somehow the real point of
the difference between ul and ol and he is right in an important sense.
From the point of view of browsers, the difference between the tags is
always and nothing but "presentational". If it sees a table tag it draws
up things in a useful manner, an ol, in one manner and a ul in another
manner. It has no concept of meaning, it is all Pavlov, stimulus of the
tag and a response in pixels or sound or braille formation. If you
remove all the responses that distinguish it from the response to a ul,
you have made it useless.

In other words, if authors keep on leaving out the numbers, they are
undermining the very purpose of the ol tag. If they are authoring for
visual users but use it in case this helps the blind (the voice reader
utilizing the tag to deliver the message of order), it is fine to leave
out the numbers as long as the context or their explanations outside the
list makes things clear.