When viewing survey results, or participation by demographic, you may see a category called 'Not Specified' in your reports.
This represents the group of people that have taken the survey, but there was no demographic value assigned to them for the selected demographic group. The platform doesn't have a category for them, so they are bundled together as 'unknowns'.
This is a data issue, and can be rectified by improving your employee data.
You will need to update your employee data and assign everyone to a demographic category if you want to avoid the "Not Specifieds".