Hi, The mix:referenceable type has the effect of enforcing, on any node
to which it is assigned, the presence of a property called jcr:uuid. The
jcr:uuid property is a protected, auto-created, mandatory property. This
means that it is created and administered by the system and can only be
read (but not changed or deleted) by the client. The job of the jcr:uuid
property is to expose the universally unique identifier (UUID) of its
node. The UUID of a referenceable node is assigned on node creation...