Tags and keywords
A ValueType is a special extension of the UML DataType:
Please note again that:
SysML-1.6: 'In SysML, unless you MUST use a DataType or PrimitiveType from an existing ModelLibrary or Profile, you SHOULD probably be using a ValueType, Enumeration ValueType, or SysML PrimitiveValueType instead so that it integrates with the value system of SysML.'Note that, in general, a DataType, and thus a ValueType, being a Classifier, may have Features such as Operations and substructure:
SysML-1.6: 'A SysML ValueType may define its own properties and/or operations, just as for a UML DataType.'But see next about PrimitiveTypes.