From their CS department, per the above page: 'I've reached our to our developers and engineers, since this is a highly unusual question. They have confirmed

From their CS department, per the above page: 'I've reached our to our developers and engineers, since this is a highly unusual question. They have confirmed that our system does not allow that character, and that this is an intentional decision. They provided the following reason as an explanation of why that decision was made: "It is a security issue. We do not allow the special characters so that hackers cannot do SQL injection in the field"