From SPCodex, The Smashing Pumpkins wiki

Template to display banter on live show pages. This should always go under the "Banter" section (level 2). There are no arguments to this template.

This template writes to Special:CargoTables/live_banter which is basically only defines which pages have banter. Hence, if banter is unknown, do not use this template and instead write (unknown) under the Banter section.