Data Tables using superscript and footnotes

HI –

I have a question on data tables that utilize superscripts and associate
them with footnotes. This stems from a recent review of annual reports
containing different superscripts (appended to column headers within<sup>
tags) and footnotes (within <tfoot>). These tables are large and run into
hundreds.

The result: Table navigation worked well, but determining the superscript
and programmatically associating it with its footnote was an issue.

To discover as well as associate the superscript with the footnote, some
recommendations were proposed:
1.       Display the superscript as a link and load the footnote information
in a pop up (note: an accessible pop up). This would preserve the tab order
after the user closes the pop up, and allow the user to continue with table
navigation, OR,

2.       Provide instructions before the table. Explain each superscript
association with its footnote as a list item. Put this info below a header
text, OR,


3.       Display the superscript as a link but style it as plain text. Use a
blank href attribute on the superscript, and supply footnote as the title
attribute.
The sticking point with #1 is that it will involve major code updates.
Similarly #2 and #3 are not perfect solutions.
Any suggestions are welcome.

Thanks,

Devarshi