+ # The short (unqualified) name of this model entity.
+ #
+ # The short-name is based from the identifiers used to declare or denote the entity.
+ # It is usually globally ambiguous but is often enough in a precise local context.
+ #
+ # It is suitable to use the short-name in message to the user.
+ # However, special care must be used in case of potential ambiguities or name conflict.
+ fun name: String is abstract
+
+ # A fully-qualified name of this model entity.
+ #
+ # The full-name is based on the short name and is usually prefixed by the name of an outer entity.
+ # Usually the quad (`::`) is used to separate the different names.
+ #
+ # The full-name is expected to be unique and unambiguous in lawful Nit models for the same kind of entity.
+ #
+ # It is often suitable to use it in message to the user.
+ # However, some full-name could be long and verbose,
+ #
+ # See the specific implementation in subclasses for details.
+ fun full_name: String is abstract
+
+ # A fully-qualified C-like identifier of this model entity.
+ #
+ # The C-name is a name that respects the rule of identifiers in the C language:
+ # it is only made of alphanumeric characters and starts with a letter (or a underscore).
+ #
+ # The C-name can be seen as a mangled version of the `full_name`.
+ # Therefore, it is expected to be unique and unambiguous in lawful Nit models for the same kind of entity.
+ #
+ # The C-name is used by tools that need some identifiers in generated files to designate the
+ # entity.
+ #
+ # Is is not suitable to use it directly with the user (e.g. in message) and
+ # indirect use should be restricted (e.g. to name a web-page)
+ fun c_name: String is abstract
+
+ # A Model Entity has a direct link to its model
+ fun model: Model is abstract
+end
+
+# Something that represents a concern
+abstract class MConcern
+ super MEntity
+ # The concern that contains `self` or null if `self` is the root of the concern hierarchy
+ fun parent_concern: nullable MConcern is abstract