[O] ical export not respecting tags

[Sample Hampton]

Users,

I am fairly new to org, but I am getting a pretty good handle on it.  I 
am having an issue with ical export.  When I export to html my tags (the 
only one of which I am using is :export:) is respected.  In the 
resultant html file only those entries and trees with the :export: tag 
are displayed.

When I export to ical, however, everything in the .org file is 
displayed.  From looking at the manual it would appear that I need to 
configure the variable "org-icalendar-categories", but I do not know 
what that piece of language would look like.

I would immensely appreciate the help of the list with this issue.

Thank you,
Sample