release listing available for freebsd-update(8)

[hulibyaka hulibyaka]

Whether there is a method of reception of the list of the releases
accessible to updating through freebsd-update(8)? For example, if open
http://update5.freebsd.org catalogs "to-N.M-RELEASE\*" are visible -
where it is possible to be updated. But it well thanking for Indexes
options on the WEB server - for an example http://update1.freebsd.org/
will not allow to see anything. It would be fine to deduce the list of
accessible releases by freebsd-update (8)