I'm setting up a study for an X-linked disease. The population will be only male, and as part of study setup, I indicate that Sex is not required. However, it still appears as an field on subject entry. Normally I wouldn't be concerned with this, it would just be extraneous data, except that the nature of the study means that if a female is enrolled, that should raise some red flags and/or be reported as a deviation, none of which am I able to do within the system at subject creation. Is there a reason that sex does not have an option for "Not used" on the study build page like DOB, Person ID, etc.?