There are two main royal flags, one for the King of Thailand, Bhumibol Adulyadej, popularly known as the "Ninth king" (Rama IX), and the other for Queen Sirikit. Both flags are in plain colors with their respective royal cyphers. Other members of the royal family, like Crown Prince Maha Vajiralongkorn, Princess Maha Chakri Sirindhorn and Princess Chulabhorn Walailak also have their own plain-color flags, but these are not seen very often, except at ceremonies personally led by them.
The royal flags are not only used officially, but also unofficially. They are displayed by Thai citizens of any social class or background at any location, usually beside the Thai flag, as a homage to their King and Queen. Honoring the royal family is a characteristic feature of Thai culture.
These flags are sold at most small stores and grocery stores in every town and village of Thailand. They come in many different sizes. Usually the symbol is printed only on one side of the flag.