Commas in FORMAT specifications (The GNU Fortran Compiler)

#### 5.1.5 Commas in `FORMAT` specifications ¶

To support legacy codes, GNU Fortran allows the comma separator to be omitted immediately before and after character string edit descriptors in `FORMAT` statements. A comma with no following format descriptor is permitted if the `-fdec-blank-format-item` is given on the command line. This is considered non-conforming code and is discouraged.

           PRINT 10, 2, 3
    10     FORMAT ('FOO='I1' BAR='I2)
           print 20, 5, 6
    20     FORMAT (I3, I3,)