It seems like these rules don't have any effect, so requests to /icons get 404'd atm on my server.
I have the same issue, links to icons are to icons/[...].png and the icons are saved as /data/icons/[...].png
I haven't found where to make the change, yet. Would be happy to get it solved.
@iohannis: The code in the .htaccess is intended to rewrite the requests to /icons to /data/icons. Doesn't seem to work tho.
I figured out that the path /icons seems to be something "reserved" (Apache?), because rewriting /favicons to /data/icons works flawlessly.
Another confirmation for my theory is that i get errors about /is/default.htdocs/icons-used-by-apache/... being unavailable.