Common metadata is shared and used across catalogs, platforms and applications by access or automatic synchronization; underlying data is understood the same way on every platform; metadata policies such as access controls and enrichment such as data quality analysis are applied automatically across platforms; and accessible data can be discovered across catalogs. This rests on catalog naming standards and an information model built on open standards in wide use (the CDMC Information Model), maintained under change management, and on system-level interfaces (APIs, events, semantic web traversal) with interchange protocols that manage mutability, mastering and synchronization so the source of truth is not lost. Procedures exist to onboard a new external application, onboard a new catalog and migrate catalogs. Metadata shared this way stays under entitlement, privacy and security policy, tenants are isolated, and one provider's usage metrics are not shared with another.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.