Observed change in Asc() function in Word 2003

[bobp0303]

Up to about a month ago Asc(selection.text) caused an error if the current
selection was an XML tag. I trapped the errors and skipped over the tags --
no problem.
Sometime in the past 30 days or so one of the multitudinous automatic
updates to MSWord has changed this function to return value 1 when a tag is
the current selection.

My question is how can I find the documentation for each update so I can
modify my code before my users complain?

Thanks in advance.