Combining public and private paths

Dear Colleagues,

I am trying to setup the following policy: a private repository with
some public paths. Is such configuration supported at all?

The following configuration:

========== conf/svnserve.conf:
anon-access = read
auth-access = write
authz-db = authz

========== conf/authz:
[/]
@noc = rw

[/foo]
$anonymous = r
$authenticated = rw

does not work. A valid user from the noc group receives the following reply:

$ svn diff -c2237 www.txt
svn: Unreadable path encountered; access denied

If I change "anon-access = read" to "anon-access = none", it begins to
work for the valid user, but there is no anonymous access to anyone
even to svn://myserver/foo despite the "$anonymous = r" clause.

What am I doing wrong?

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov_at_sibptus.tomsk.ru