Varnish 2.06 running away with memory

[andan andan]

2010/5/19 Per Buer <perbu at varnish-software.com>:
> No. 2.1 still uses memory for keeping around 'bans'. Note that Varnish
> will discard bans older then the oldest object in the cache. If you
> keep your TTLs somewhat short memory usage will be lower.
>
> In 2.1 Varnish can 'nuke' all variants of a page through in a ttl=0 manner.

Please, can you give more details on this point or give a link to the
documentation.

Thanks in advance.