It is the registration identification of the vessel
The vertical pole on a sailboat is called the mast, but at the bottom of the sail is horizontal pole called a boom. On the Tall Ships, the horizontal pole AT THE TOP of the sail is called the yardarm.
A headstay is a critical component of a sailboat's rigging, serving as a wire or rope that runs from the top of the mast to the bow of the boat. It helps support the mast and provides stability, particularly when sailing upwind. The headstay is typically used in conjunction with the forestay, and it can be adjusted to control the shape of the sail and improve performance. This rigging is essential for maintaining the integrity and balance of the sailboat while under sail.
That would be the deck.
masthead
At night, a sailboat should display a combination of navigation lights to ensure visibility and safety. This typically includes a white stern light at the back, a red light on the port side (left), and a green light on the starboard side (right). Additionally, if the sailboat is under sail, it may also show a white all-round light at the top of its mast. These lights help other vessels determine the direction and status of the sailboat.
Topgallant sail, also known as the gallant sail or garrant sail
It is on top of the pet shop
The anchor light at the top of the mast should not be used by a sailboat underway at night. Frequently it is left on when leaving an anchorage along with the steaming and navigation lights.
its all of the letters on the keyboard from top left to bottom right
The mizzen is the third mast on a ship, or the mast immediately aft of the mainmast. The top sail on that mizzenmast would the mizzen-top. Your local slang may vary.
in the top left hand corner
Do you mean the bar on top with letters in it that start with "HTTP"? If that is what you mean, that is your address bar where you can type in a website's URL.? Or maybe you mean something else