Footnotes and sectioning roots. <figure> and <table>

The draft text has a section with recommendation about footnotes. Those 
recommendations do not give any advice about footnotes inside elements 
that belongs to the "Sectioning roots" category. Just as headers of a 
sectioning roots element do not take part in the general outline of the 
document, it also seems logical that links inside such elements should 
be kept inside the element itself if the links are of "footnote nature".

In particular the figure element, which represents a sectioning roots 
element that  "can be moved away from the main flow of the document 
without affecting the document's meaning", needs footnotes advice.  
Because, if  the footnote of a <figure> is placed outside the figure 
element itself, then it isn't possible to move the <figure> out the page 
without affecting the document's meaning. If the figure was removed, and 
the footnote natured notes remained in the page, those notes would be 
entirely meaningless. The draft should say that footnote natured links 
inside a figure element should point to footnotes inside the figure 
element itself. (This does not prevent that the figure could contain 
links that points to other, independent texts outside the figure element.)

Figure elements used as table containers should be given special 
attention. Firstly, table footnotes is a feature that is sought for - 
see for instance Ferg [1].  Text in table cells often needs to be short. 
Thus a link to a footnote might be required to explain what the short 
text means. Such footnotes needs to be close to the table. The best 
advice is probably that such tables are placed inside a <figure> 
element, and then that the footnotes are placed immediately after the 
table. It does not seem right to use <tfoot> for this, and the draft 
should speak against use of <tfoot> for that.

But such table footnotes would also affect the use of the <caption> 
element, however, as the the draft currently says that "When a table 
element is in a figure element alone but for the figure's legend, the 
caption element should be omitted in favour of the legend." Thus, if 
table footnotes are placed inside the <figure> element - as they should, 
it is suddenly no longer conforming to use the <legend> as caption of 
the <table>. Thus the draft should, in addition to <legend>, also allow 
table footnotes inside such figure elements.

Using <figure> as a table container begs another question however: 
display. The CSS display of <figure>  and <legend> is block. But 
whenever the <figure> is a <table> container, then a 
figure{display:table} seems more appropriate, to ensure that the legend 
looks like a caption to the table.

[1] http://www.ferg.org/section508/htp04_proposal.html
-- 
leif halvard silli

Received on Sunday, 3 May 2009 03:39:40 UTC