UMLR — Ambiguous stereotype notation

Suppose we have a stereotype S extending UML::Class.
We can apply S to a UML::Class, UML::Activity, UML::StateMachine and any other element whose metaclass is a kind of UML::Class.

The UML notation for stereotype allows showing applications of S as <<S>> but this notation does not clearly show what kind of element the element is.
In cases where distinct metaclasses (e.g., UML::Class, UML::Activity, UML::StateMachine) use the same notation (i.e. a box), the overall notation is ambiguous.

The UML notation could be extended to show optionally the metaclass of an element, e.g., <<S>> [Class] vs. <<S>> [Activity] vs. <<S>> [StateMachine].

Proposed resolution:

in clause 18.3.9, Stereotype, under notation, change:

When a stereotype is applied to a model element (an instance of a stereotype is linked to an instance of a metaclass),
the name of the stereotype is shown within a pair of guillemets above or before the name of the model
element, or where the name would appear if the name is omitted or not displayed. For model elements
that do not have names but do have a graphical representation, unless specifically stated elsewhere, the stereotypes
can be displayed within a pair of guillemets near the upper right corner of the graphical representation.
If multiple stereotypes are applied, the names of the applied stereotypes are shown as a comma-separated list
with a pair of guillemets. When the extended model element has a keyword, then the stereotype name will be displayed close to the keyword,
within separate guillemets (example: «interface» «Clock»).

to:

When a stereotype is applied to a model element (an instance of a stereotype is linked to an instance of a metaclass),
the name of the stereotype is shown within a pair of guillemets above or before the name of the model
element, or where the name would appear if the name is omitted or not displayed optionally followed by the name of the
model element's metaclass within a pair of square brackets. For model elements
that do not have names but do have a graphical representation, unless specifically stated elsewhere, the stereotypes
can be displayed within a pair of guillemets near the upper right corner of the graphical representation optionally
followed by the name of the model element's metaclass within a pair of square brackets.
If multiple stereotypes are applied, the names of the applied stereotypes are shown as a comma-separated list
with a pair of guillemets. When the extended model element has a keyword, then the stereotype name will be displayed close to the keyword,
within separate guillemets (example: «interface» [Interface], «Clock» [Class]).