SYSML2_ — Inconsistent use of guillemets in graphical notation for metamodel aspects

The graphical notation makes use of enclosing guillemets to mark up presentation of the metaclass as well as possible metaproperties and metamodel extensions of a model element (i.e., their mapping to the SysML abstract syntax or metamodel). However, there are inconsistencies in their application. The following graphical BNF productions are affected:

• -name-compartment productions,
• -edge and -relationship productions,
• productions including user-defined keywords that extend the metamodel.

Currently, metaproperties of a metaclass are treated in different ways. E.g. in a -name-compartment the isAbstract metaproperty is presented as a leading '«abstract»' literal with its own guillemets, while the isReference metaproperty is included in the main metaclass presentation, e.g., '«ref part»'.

A single, consistent rule should be established for all graphical BNF productions that concern presentation of metamodel information.