nonobligatory

unrestricted

at the call elective facultative judge and jury leftover nonmandatory open optional

nondiscretionary

electoral

constituent voluntary voting

discretionary facultative not compulsory optional selective

required

discretional discretionary elective noncompulsory not required volitional voluntary

alternative arbitrary discretional discretionary elective extra facultative free no strings attached noncompulsory not required open unforced unrestricted up to the individual volitional voluntary

compulsory forced required