The preprocessor produces MF COBOL II source code in ANSI format using certain conventions. Indicators for comments and continued string literals are placed in column 7. The 01 level number for data declarations known to the preprocessor is output in Area A, starting at column 8. All other generated statements are placed in Area B, starting at column 12. No statements generated extend beyond column 72. COBOL statements and declarations unknown to the preprocessor appear in the preprocessor output file unchanged from the input file.

The preprocessor does not generate any code in columns 1 - 6 (the Sequence Area). Do not, however, precede EQUEL statements with sequence numbers—the ## signal must always appear in the first two columns. Also, although the preprocessor never generates code beyond column 72 no matter which format is used, it does accept code in columns 73 - 80. Therefore, anything placed in that area on an EQUEL line must be valid EQUEL code.