emqx4.3/changes/ce/feat-13923.en.md

Added zone to authentication, authorization and mountpoint template.

Prior to this change, if one wants to use zone name in authentication or authorization rules, they would have to use client_attrs. Now ${zone} can be used directly in authentication and authentication.

As an example, here is an ACL rule making use of zone: {allow, all, all, ["${zone}/${username}/#"]}.