consumerid is not "required" in the spec

[jordig100]

The spec says:
A consumer MUST be identified by "consumerid", an attribute in element, where consumerid is a human readable unique identifier (Alphanumeric). Each consumer is expected to have a unique id, which is known to both producer and consumer.

But it is not defined as required in the schema, which is contradictory,

[jordig100]

To define as required in both the schema and in the table.