Symmetrical voice
Symmetrical voice, also known as Austronesian alignment or the Austronesian focus system, is a typologically unusual kind of morphosyntactic alignment in which "one argument can be marked as having a special relationship to the verb". This special relationship manifests itself as a voice affix on the verb that corresponds to the syntactic role of a noun within the clause, that is either marked for a particular grammatical case or is found in a privileged structural position within the clause or both.