Wiktionary, like any other dictionary, documents what terms mean in practice, not what they might mean based on their form.
Defining 9/11 as the 11th of September or the fraction nine elevenths, and linking to a general article on the date September 11th is simply incorrect. I note that the original contributor did not contribute articles for 6/4, or 13/583 or any other possible fraction or date. Why, pray tell?
For better or worse, 9/11 is understood to mean 11 September 2001. This is certainly universal in the US. I believe it is sufficiently widespread in the rest of the English-speaking world (and to at least some extent beyond) that in the absence of other cues a phrase like "remember 9/11" or "the events of 9/11" would be taken as referring to 11 September 2001 and not November 9th.
If this is not the case, than I'd add the tag "US" (and probably change Translingual to English)
-dmh 06:42, 7 Nov 2004 (UTC)