Another major obstacle arises when multiple XSD documents need to be processed to deal with different schema namespace design approaches, where the targetNamespace count can range from zero to many.

At the last count 138 galleries from 30 countries had signed up. They range from established shops like London's White Cube and new York's David Zwirner to relative newcomers such as i8 in Reykjavik.

And that does not count related parts like the system that maintains the temperature of the cells within an acceptable range and manages the charging and discharging.