UML25 — Name without a colon for Property in Composite Structures

In Composite Structures, under 9.3.12 Property, the following
paragraph under "Presentation Options" under "Notation" is
inconsistent with the rest of UML in creating a special
interpretation of a missing notation element:

"A property symbol may be shown containing just a single name
(without the colon) in its name string. This implies the
definition of an anonymously named class nested within the
namespace of the containing class. The part has this anonymous
class as its type. Every occurrence of an anonymous class is
different from any other occurrence. The anonymously defined
class has the properties specified with the part symbol. It is
allowed to show compartments defining attributes and operations
of the anonymously named class."

The simple omission of notation elements is part of the option
in virtually all UML diagrams to elide elements that aren't
relevant or are defined and shown on other diagram views.
Implying something to be created by the absence of an
element breaks from user expectations.

In this case, the most natural expectation of a simple name on
a property box, without any colon, is that the string is just
the name of the part or property, and that the type for the
name, ordinarily shown using a ":Type" string, has been omitted
from the diagram.

The simplest way to resolve this issue is just to remove this
paragraph from the specification. The specification would then
revert to the default interpretation of a missing notation
element, which is just that it isn't shown on a particular
diagram view, not that it doesn't exist.

The application of Composite Structure diagrams to systems
engineering, in response to the UML for Systems Engineering
RFP, expects to use all the flexibility that UML provides to
include or not include diagram elements on particular views
of a complex system, to avoid cluttering the many partial
views that might be needed. Resolution of this issue is
essential to avoid having a different rule for a name without
a colon in standard UML vs. its application to systems
engineering.

The BNF for Property does make the [’:’ <prop-type>] optional, so this is indeed an inconsistency in the
spec. Delete the offending paragraph