Ricoh D131 Service Manual page 1511

Details
FM3 Letter Fold-out
In Fold Method 3 (FM3):
The leading edge of the paper is stopped by Fold Stopper 1.
The paper flexes toward the nip of fold rollers
Fold Stopper 2 stops the paper and flexes it into the nip of fold rollers
Fold rollers and
Fold Stoppers 3 is not used.
D454/D615
perform the second crease and feed the folded paper in exit path.
118
and which performs the first fold.
and .
SM