Modelio supports UML communication diagrams, which are used to illustrate architecture and its functioning principles, by presenting, for example, which associations are used to transmit which messages between which elements.
Communication diagrams partially cover the capacities provided by sequence diagrams, but are less relevant when detailing event sequences and messages between several participants. They are most often created in collaborations, operations or internal class structures to describe the principles of the dynamic.
Communication diagrams have limited capacity in terms of showing sequencing, choices or loops, being structured or referencing themselves. For these purposes, sequence diagrams are more appropriate.