I posted this in the general forum 5 days ago, 37 views and no responses, so I guess it's a feature request.
I want to be able to say things like "see footnote 23" and have the number automatically update if I add or delete other footnotes (easy in FrameMaker). But the New Cross-Reference window displays the list of paras with format "Footnote" with tiny bullets where the numbers should be, and entering a cross-ref with format "Paragraph Number" to a paragraph with format "Footnote" just produces a blank in the text. Please add the ability to x-ref footnote numbers (or tell me what I'm doing wrong).
Three years on, and still no cross-references to footnote numbers. Switching from FrameMaker only recently I have to say this was a bit of a nasty surprise.
My solution involved, alas, spending more money. A company called DTPTools makes a variety of ID plug-ins and utilities, including one called Cross-References Pro (http://www.dtptools.com/product.asp?id=crin). 99 euros but well worth it: it solved a number of problems I had with limitations in ID's x-referencing, including the one about footnote numbers I complained about, as you observe, three years ago.
I should have added: DTPTools' customer support is excellent.