What you saw is Alternate Control which changes the controls to require diagonal inputs (so d,b+1 becomes d,db,b+1) but also allows you to charge the first input (so if you are holding down for a few seconds you can use that for the first input of d,b+1, regular controls you need to let go of down and press it again)
And FYI the other option is Release Check which is commonly known as Negative Edge, meaning when you have the release of a button press count for the press of a button press. Only applies to special moves.
