Gerber format options that to be selected.

The Device type field specifies the plotter model: Gerber 274 X is used mostly this is dependent on the format the manufacturer requires the file

Suppression :

The Suppress fields control whether the PCB Editor tool writes leading or trailing zeroes or equal coordinates in the Gerber data file. You cannot suppress both leading and trailing zeroes. Selecting Equal coordinates reduces the size of the Gerber data file.

Any zeroes appearing to the left of the first non-zero digit (of any integer or decimal) do not affect its value, and can be omitted: Suppress leading zeros

similarly the trailing zeros after the decimal point non-zero digit which can be insignificant: Suppress trailing zeros

If there are more than one data at a specific coordinate then the coordinates are not repeated in the Gerber file: Suppress EQUAL  

SUPPRESS-LEAD-ZEROES  YES

SUPPRESS-TRAIL-ZEROES NO

SUPPRESS-EQUAL   YES

Thanks