The that represents the top of the hierarchy of .
The top level of the metadata hierarchy represents broad groups of metadata as follows:
138875005 |SNOMED CT Concept| //* ⬅︎ The root concept *// 900000000000441003 |SNOMED CT Model Component| //* ⬅︎ The root metadata concept *// 106237007 |Linkage concept| //* ⬅︎ Attributes and other linkage concepts *// 370136006 |Namespace concept| //* ⬅︎ Concepts representing namespaces *// 900000000000442005 |Core metadata concept| //* ⬅︎ Metadata supporting components *// 900000000000454005 |Foundation metadata concept| //* ⬅︎ Metadata supporting refsets *// |