On 19.4.2012, at 2.11, Joseph Tam wrote:

I noticed the addition of a new namespace configuration "alias_for". What pracical difference is adding this over and above making namespace aliases hidden and disabling list, as in older versions of dovecot configurations?

It's used by doveadm and dsync to skip duplicate mailboxes. I've also been thinking that it could be made automatic by comparing which namespaces have identical "location" settings.