Hard Commit F41021

Hi,

i have this sales process:

1) Sales Order Entry status 520

2) Sales order shipping 560

3) Print Inovice

4) Sales Update R42800

i notice today that for the first time the field HARD COMMIT on the F41021 is populated with few quantity.

Why is hard commit populated? what does it mean hard commit? and when occur to have some value in the hard commit field?

Thanks