Inconsistent requirement for Contact.date_of_birth
Date of birth is currently required for all subjects except for guardians. This exception was made for historical reasons.
Date of birth is used for two things:
- subject distinction: a name alone is not unique. This is used in subject search and duplicates maintenance view
- full age: subjects under the age of 16 need a guardian. Once they become full of age their consent needs to be renewed.
The second case is mostly unproblematic because underage subjects usually are not guardians and therefore are required to have a date of birth.