PATCH endpoints, such as Update service, are used for updating existing resources. Individual endpoints pages will document further how to use these endpoints effectively, but there are some rules that apply to all of our PATCH endpoints.
PATCH endpoints are not used for updating nested resources. For example, if you want to manage custom domains for a service, you wouldn't do this through the Update service endpoint, but would instead use the Add custom domain and Delete custom domain endpoints.
What gets updated?
If you include a field in the body of a PATCH request, it will be updated on the resource. This is true even when you include a field, but leave it null/empty. In this case, the request will be understood as wanting to remove or unset that field.
If you don't include a field in a PATCH request, it won't be changed or unset.