Carlo Gesualdo

The Islamic militants known as ISIS have shown savvy in social media and in picking their symbols. We explore the deeper meaning behind their index finger salute — and their black-and-white flag. And an author shows a side of Iran’s capital that you might not have expected, from sex to drugs to skinny jeans. And are you tired of being cramped in economy class? You’re not alone. All that in today’s Global Scan.