Data Models

Models are versioned specifications or implementations
They can be:

• class diagrams (conceptual)
• reference data
• ontologies

They can be associated with the following design documents:

• schemas
• documents
  • word
  • excel 
• database dll 
• uml diagrams
  • logical
  • physical
• forms definitions i.e. html forms or other media
• swagger specs etc. 

They can also have a number of implementations associated with them:

• apis
• databases 
• applications

The following are also considered implementations:

• software (code in a repository)
• data processing systems (data quality tool or service bus)

They are published and are the "top" of the publishing hierarchy.
They are versioned, released, implemented can be finalised, draft or deprecated.
Models have a number of policies that apply to them to ensure that all the elements associated with them are consistent.
Imports:
They have direct imports i.e. a consciously imported data elements from another domain
Often models will contain a release note that lists all the changes, the associated design documents