To be fair, I’m not really sure if Michel Aoun’s Free Patriotic Movement were the first ones to adopt the check mark hand sign (as seen below),
But it seems Bahrain’s parliamentary hopefuls have also decided to join the sign language:
It’s pretty apparent that they read How to Create a Successful Lebanese Political Party: The Complete Guide especially part one, point four:
Remember that party flags and other coloured pieces of cloth are not always available. Therefore think of a clever hand gesture or finger sign that will allow your party members to recognize each other without resorting to words.