[squid-users] acl aclname user ??? does this exist?

The squid.conf doco list of acltypes has an acltype of "user". There is no
explanation of this acltype & I got a parse error when trying to implement
it. Does it in fact exist?

I want to match an acl against the authenticated user cache. Is it
possible? (I thought mabe that was what the "user" acltype was) or do I have
to do selective authentication before:
acl password proxy_auth REQUIRED

--
Greg Cunningham BAppComp, RHCE   ph +61 3 6440 7453
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Harris & Company Pty. Ltd.       mo    0407 056 788
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