Changing a Radio Button field to a NIL value

I have a Non Required Radio Button field with 5 options, but sometimes I don't want any option chosen and creating a sixth option named NIL looks like it can not be avoided in the Filters for this field.

How can I do so a HikaMarket vendor can transform the already selected Radio Button to NIL value?

Hi,

I don't understand the reference to HikaMarket vendor, but the best solution for you will be to add some Javascript in order to unselect the radio.
I could be possible to do such thing by modifying the HikaShop core but it is not something recommended because after that, you couldn't update HikaShop without loosing your modification.

Regards,