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FAQ: Why does the classifier-level Block stereotype show on parts in an IBD ?

When no "instance-level" stereotype has been applied to a Property the Stereotype of the Type (in this case «Block» applied to a Class) of the Property "shows through", as can be often seen on Property symbols in SysML Internal Block Diagrams (IBDs) and structure compartments. This is sometimes called a secondary Stereotype.

This is reminiscent of the translucency pattern of object-oriented programming, where a field or property of a class takes the static value defined on the owning class until it is explicitly set on an object.

Dr Darren has proposed that UML™ notation could be improved by always showing such secondary stereotypes with a preceding colon, like «:Block».