Examples:

  comm -12 file1 file2  Print only lines present in both file1 and file2.

  comm -3  file1 file2  Print lines in file1 not in file2, and vice versa.

comm -3 prints lines that are unique to both file1 and file2 in separate columns.

comm -23 prints the lines that are in file1 and not in file2.

I hope the correction will be made soon enough.

Regards,

Bhargav.