"🇴🇸-🇩🇴-4️⃣0️⃣" represents the combination of the flag emojis for Australia (🇴🇸) and the Dominican Republic (🇩🇴), along with the numbers 4️⃣0️⃣. It could be interpreted as a symbolic representation of the fusion between these two nations or a reference to an event, milestone, or anniversary involving both countries.