[NAF] Reference architectures reflect strategic decisions regarding system technologies, stakeholder issues, and product lines. They render user requirements, processes, and concepts in a high-level solution from which individual projects can be identified and initially programmed. Their primary focus is on services, processes and component functionality, and they provide the basis for the development of Target Architectures (TA).

Architectures which are used as a reference for a large set of applications.
The following qualifiers may be used to distinguish domain-specific and domain-independent architectures:
- Domain-specific: architectures that target a very specific application domain, e.g. land-based entity level simulation : DIS, TENA
- Domain-independent: architectures that are (at least to some degree) independent of a specific application domain : HLA
Additionally, architectures may be qualified as ?comprehensive? if they define additional services, service agreements, and/or service components : VIntEL, NETN, MTDS, (ELLIPSE ?)