For marketing, it should have whatever the marketing/dataminers want to know about your purchasing preferences. Male, female. Then "Don't specify". If you're d

For marketing, it should have whatever the marketing/dataminers want to know about your purchasing preferences. Male, female. Then "Don't specify". If you're datamining or have specific products for specific nonbinary consumers, add that. For science and health, be as specific as required or ask for biological sex and demand "male" or "female" as appropriate. (IMO).