Mano Destra in Piano Music Notation

In piano music notation, mano destra (M.D.) indicates that a section of music should be played with the right hand rather than the left hand. Mano destra is an Italian term; literally speaking, mano means "hand" and destra means "right," together meaning "right hand." Sometimes this technique can also be indicated in English, where it would be "R.H." for right hand, in French, where "M.D." stands for main droite, or in German,  where "r.H." means rechte Hand. There is a similar term which means that music should be played with the left hand which is mano sinistra (M.s.). 

Typically in piano music, notes that are written on the bass clef is played with the left hand and music notated on the treble clef is played with the right hand. But sometimes, the music may call for the pianist to use both hands in the lower bass register, or even for the right hand to cross over the left hand to play the bass notes. Another time when M.D. is used in music might be if the left hand had been playing on the treble clef and it is now returning to the bass clef. M.D. would be placed near the treble clef to indicate the return of the right hand to the treble clef notes.