This is the flag of the Dutch island territory of Saint Martin. Sint Maarten is the self-governing kingdom the Netherlands, and its flag consists of two identical trapezoids in red and blue on the right. It consists of a white isosceles triangle on the left, with a blue island emblem in the triangle, and SX is displayed on some platform systems. It generally means Dutch Saint Martin.
🇸🇽 is the Emoji of a country/region‘s flag, and its meaning is flag: Sint Maarten. The Emoji 🇸🇽 is composed of two regional indicator letters, namely 🇸 and 🇽. The country/region's 2-letter code for Sint Maarten is SX, so the letters corresponding to the two region indicator letters are S and X. 🇸🇽 is displayed as a whole flag on most platforms and as a two-letter symbol on a few platforms.