The standardized fixed format for writing COBOL programs can be described in terms of a line consisting of 80 character positions. The compiler only accepts COBOL programs written in the reference format and generates a listing of the program in the same format.
A line is divided as follows:
Margin L
is located to the left of the leftmost character position in a line.
Margin C
is located between the sixth and seventh character position in a line.
Margin A
is located between the seventh and eight character position in a line.
Margin R
is located to the right of the rightmost character position in a line that is still relevant for the compiler.
Sequence number area
contains six character positions (columns 1 to 6) located between Margin L and Margin C.
Indicator area
the seventh character position in a line.
Program-text area
contains the character positions 12 through 72 and is located between Margin A and Margin R.