DYMM

Duli Yang Maha Mulia (DYMM) is the royal title, equivalent to His Royal Highness, used to refer to state rulers in Malaysia.

The phrase is also the title of the state anthem of Selangor, Malaysia, adopted in 1967. The lyricist is unknown but the music is by Saiful Bahri.

The first state anthem of Selangor created in 1908, recomposed from a traditional song titled Chantek Manis. The recomposing was done by Daniel Ortego who was in charge. The original lyrics are:

However, in 1966 Sultan Salahuddin Abdul Aziz Shah, the then Sultan of Selangor announced that the song will be replaced by the new song, which is now the present anthem. This anthem was the suggestion from the composition of the song by the then Director of Filem Negara Malaysia, Mr. Saiful Bahri when the Sultan paid a visit to its studio. The new anthem is named "Duli Yang Maha Mulia" until now.

...
Wikipedia