Palu is the Indonesian and Malay word for a hammer or gavel, and ketukan means a knock or tap, so the name simply describes two gavel strikes. Gavels have long been used by judges, auctioneers and meeting chairs to call for order and mark decisions. Online, this short double knock has become a handy shorthand for anything official, from parody trials and debate edits to meeting memes. Its brevity makes it easy to drop into a video at the exact moment a ruling is delivered.