The reference format for a line is represented as shown below:
The sequence number area occupies six character positions (1-6), and is between margin L and margin C.
The indicator area is the 7th character position of a line.
Area A occupies character positions 8, 9, 10 and 11, and is between margin A and margin B.
Area B occupies character positions 12 through 72 inclusive; it begins immediately to the right of margin B and terminates immediately to the left of margin R.
The program text area consists of both area A and area B. Text-words can begin anywhere in the program text area.