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
Outboard means "outside", for example, an outboard motor as opposed to an inboard engine.
Mercury is a rocky planet, unless you mean the element mercury which is a metal.
The mean concentration of mercury in the litosphere is 0,05 ppm.
What does the code P0190 mean on your 200 Mercury Mistique?
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
If you mean the Planet Mercury then the answer is YES.(And the the metal also.)