Dyna-Float was a technology of the time to help give a vibration free ride. the lower bushings keep your motor from creating that vibration feeling on older boats.
Good chance that is your Serial Number.
The year, 1990
ELPT on a 50hp Mercury 4-stroke outboard stands for "Electric Start, Long Shaft, Power Trim." This designation indicates that the outboard features an electric starting system, a longer shaft length suitable for larger boats, and a power trim feature that allows for easy adjustment of the motor's angle while underway. These features enhance the convenience and performance of the outboard in various boating conditions.
Outboard means "outside", for example, an outboard motor as opposed to an inboard engine.
What does the code P0190 mean on your 200 Mercury Mistique?
The mean concentration of mercury in the litosphere is 0,05 ppm.
Mercury is a rocky planet, unless you mean the element mercury which is a metal.
If you mean Freddy Mercury, then yes.
If you mean a 1966 American quarter, then none.
It means that mercury is denser than iron.
Indium-Mercury
Indium-Mercury