IsEligible(a;b;c) returns 1 if the participant is eligible for the contest according to the date of birth ranges and, optionally, gender, and 0 otherwise. 

isEligible("01/01/2000") - checks whether the date 01/01/2000 is eligible for the current contest of the participant. 

The function can also take a year instead of date. 

isEligible(2000) - checks whether the year of birth 2000 would be eligible for the current contest of the particpant.

The second parameter is optional and can be used to also check whether the gender is eligible for the contest. 

isEligible([DateOfBirth];"m") - checks whether the current date of birth and the gender Male is eligible for the current contest of the participant. 

The third optional parameter can be used to define the contest ID. 

isEligible([DateOfBirth];[Gender];2) - checks whether the participant is eligible for contest ID 2. 

This function is useful for registration of relay teams where additional team members information may be stored in additional fields, but you still need to confirm their eligibility to compete.