Scratch is doing the run within the time allowed. For example, if your dispatch works out to 9.45 hours and you punch out at 9.45 hours you are scratch for the day. If you punch out earlier that is called being under. If you punch out later that is called being over.
The variables that make up your dispatch hours include total stops/miles/pkgs delivered/pkgs picked up/COD's.
You will be expected to run scratch, including your paid break and unpaid meal break, during your 30 day qualification period.