What interface restrictions does a port have?

In UML composite structure modeling, a port is a structural feature that specifies a distinct interaction point between a classifier and its environment or between internal components. UML specification allows complete flexibility regarding interface multiplicity on ports. A single port can specify multiple provided interfaces (provided : Interface []) and multiple required interfaces (required : Interface []) simultaneously, allowing complex interactions to be grouped together through a single architectural port.

A: UML does not require a port to balance or match its count of provided and required interfaces.

C: Ports are not restricted to single interfaces; they can declare zero, one, or multiple provided and required interfaces.

D: Ports are not restricted to an exclusive choice between provided or required interfaces; they can simultaneously feature both types.

E: Ports are not restricted to exactly one provided interface or exactly one required interface.

- Object Management Group (OMG). (2017). OMG Unified Modeling Language (OMG UML)

Version 2.5.1

Section 11.3.3 (Ports)

pp. 182-184. https://www.omg.org/spec/UML/2.5.1/PDF

- Object Management Group (OMG). (2017). OMG Unified Modeling Language (OMG UML)

Version 2.5.1

Section 11.8.14 (Port [Class])

pp. 219-220. https://www.omg.org/spec/UML/2.5.1/PDF