The Expose namespace has Entities and Operations common to all namespaces or things that does not fit under any other namespace.
https://customer-slug.api-se.norce.tech/commerce/expose/1.1/
https://customer-slug.api-se.norce.tech/commerce/expose/1.1/ListErrorMessages
curl -i -X GET \
https://customer-slug.api-se.norce.tech/commerce/expose/1.1/ListErrorMessages[ { "Name": "string", "Value": "string" } ]