Difference between Class 1 and Class 1A Air Brake Test?

What is the difference between a Class 1 and Class 1A Air Brake test? I know the Class 1 is the test done after 1000 miles, and the Class 1A is the initial terminal test. I see the procedures for both are about the same, but what is the main difference?

Class 1 is initial terminal. 1A is a 1000 mile inspection test. All the requirements are basically the same as one another. I think a 1A is for unit trains,coal,grain ect. that basically stays in tact with the exception of setting out bad orders. At least that's what I gather reading it directly from the book.

Class 1 : http://edocket.access.gpo.gov/cfr_2006/ ... 32.205.htm

Class 1a : http://edocket.access.gpo.gov/cfr_2006/ ... 32.207.htm