The flag of the United Kingdom of Saudi Arabia contains a green field on which lies, in white, an Arabic inscription and centered below the inscription is a straight, horizontal sword which points toward the hoist (left) side of the flag. The inscription is the Islamic creed, or shahada: “There is no god but Allah; Muhammad is the Messenger of God”. It is written in calligraphic Thuluth script and a declaration of their faith.
The green of the flag of Saudi Arabia represents Islam and is used by other Islamic nations in their flags and national emblems. The sword stands for the strictness in applying justice.
The shahada is considered holy, so for this reason the Saudi Arabia flag is not used on t-shirts or other items. Nor is the flag ever allowed to be lowered to half-mast as a sign of mourning, because lowering it would be considered blasphemous. Similarly, the flags of Afghanistan, Somaliland, and Iraq are also never at half-mast. According to Saudi Arabian legislation their flag may not be hoisted vertically.
The flag is manufactured with identical obverse and reverse sides, to ensure the shahada reads correctly, from right to left, from either side. The sword points to the left on both sides, in the direction of the script. The flag is sinister hoisted, meaning that it is hoisted to the left of the flag pole, as viewed from the obverse (front) side.
The use of the shahada on the flags of Saudi Arabia dates back to the 18th century. It wasn’t until 1902 when Abdulaziz Abdulrahman Al-Saud, leader of the Al Saud and future founder of the Kingdom of Saudi Arabia, added a sword to the design of the flag. However, there were variants of the sword used on the flag until it was standardized in the 1970’s. It was on March 15, 1973 when the design used today was formally adopted by the nation.