"خط رسمی" refers to a formal letter used in professional or official communication. It follows a specific structure and tone, ensuring clarity and respect. Commonly used in business, government, and academic settings, this type of letter often addresses important matters such as requests, notifications, or complaints. The format of a "خط رسمی" typically includes the sender's address, date, recipient's address, a formal greeting, the body of the letter, and a closing statement. It is essential to maintain a polite and concise style, as it reflects the seriousness of the communication and the relationship between the parties involved.