Good Morning Pedro.
Please check on the below that might help you further on this.
As to be seen as an example:
Offering - "Employee Recognition"
Form name - "TestForm"
Form field id - "discount_code"
Form field value - "TEST"
Policy condition:
$(anySoWith('status', lteq, 800) && _.service.code=='ER' && _.sog['Employee Recognition'].serviceoption[1].form['TestForm'].discount_code=='TEST')
$(anySoWith('status', lteq, 800) && _.service.code=='ER' && _.sog['Employee Recognition'].serviceoption[1].form['TestForm'].discount_code!='TEST')
As you can see, in one condition, it is testing whether the field value is set to the same as the value attribute
(discount_code=='TEST') or if it's not the same (discount_code!='TEST').
If the check box is ticked, discount_code=='TEST' is true.
If the check box is not ticked, discount_code!='TEST' is true.
For a mandatory attachment, please check the according checkbox on the service option.
Please try this on your system and let em know if it works.
Thanks and kind regards, Louis van Amelsfort.