Bach, J.S. - Prelude BWV 939 in C Major

[@ZephyrysBaum]

What do the sharps below the ornament, and above the note head mean?

[@SenicoOcines]

u will alter the ornament with a sharp note. in this case, without the sharp in the ornament you would play G - F - G, but with the sharp in ornament you will play G - F# - G