What about Britons with EU spouses?

As a UK passport holder travelling to the Schengen area with an EU passport holder spouse what proof of marriage is required to be properly recorded in EES? Do the couple need to travel together? 

As a non-EU citizen with an EU passport holder spouse, to be properly exempted from normal EES limitations (90/180 rule), you must provide official proof of the family relationship, such as a marriage or civil partnership certificate (preferably in multilingual format or with certified translation if not in the language of the border official).

To benefit from the EES exemptions as a family member, you must be travelling together, or you must be joining the EU citizen in the Schengen area. 

Remember that exemption from the 90/180 rule applies only if you are exercising your right to accompany or join your EU family member. You must still be registered with EES.