The framework assumes that there could be multiple publishers of business meta-data and e-business capabilites. Therefore a simple way to ask "where can I find information about the e-business capabilities of business X ?" is needed. That is the purpose of the DCL. It is essentially a DNS lookup (NAPTR Record) using a business identifier (eg ABN) as the query and it returns the URL of the detailed metadata about that business. In a given economy, there is usually only one DCL - often operated by a government authority.
Specification: http://ausdigital.org/specs/ausdigital-dcl/1.0/
Community discussion/support: ausdigital.org
Open source reference implementation: https://github.com/test-point/testpoint-dcl/
Test suite: https://github.com/test-point/testpoint-dcl
Live test endpoint: https://dcl.testpoint.io/