where no nli is required some schools as a courtesy to the player use their own "commitment letter"
so the walk on or player receiving all academic $$ has a document to sign at his HS for parents newspapers etc
is it binding & would other schools honor it? nope - there is nothing to honor - it's only a "courtesy show document"
the nli program has 500+ member schools,
the courtesy letter progam has 1 member (themself)
if what your friend signed is in fact a school's courtesy letter, he still has options
however - a good rule of thumb is - understand what you are signing
good luck
lefties? - - - they just aint right!