"DH" button on an elevator?

Question

What does the "DH" button do on an elevator? I thought it might stand for Door Hold, but there's already the "<->" button that holds the doors open. Does this button do the same thing?

Answer 1

We have the same question with our renovated elevator.  When I push the DH button nothing visibly happens.  We don't have a dining hall in our building but I'm holdng out for a dog house someday ;-)