| SAbstractConcept | A descriptor of a concept. | 
| SAbstractLink | Represents an abstract meta-definition of node connections. | 
| SConcept | Represents a concept | 
| SConceptFeature | Member of a concept, named. | 
| SContainmentLink | Containment links describe parent-child relationships. | 
| SDataType |  | 
| SEnumeration | Represents an enumeration - a collections of related options (SEnumerationLiterals) | 
| SEnumerationLiteral | Represents an option in an enumeration | 
| SInterfaceConcept | Represents an interface concept | 
| SLanguage | Reference to a deployed/run-time language. | 
| SNamedElement | A named meta-object | 
| SPrimitiveDataType | It represents primitive data types, such as int, string or boolean. | 
| SProperty | Represents a concept property | 
| SReferenceLink | Reference links describe relations that do not follow the parent-child relationships pattern. | 
| SScope | Scope provides a set of nodes, visible in the particular context. |