A Comment is a textual annotation that can be attached to a set of Elements.
In UML 2.5 and SysML, the Comment is provided as a definition type and a symbol type that can be drawn on a diagram. A comment gives the ability to attach various remarks to elements. A Comment is shown as a rectangle with the upper right corner bent.
The Comment can be associated with model elements through the relationship type:
•Comment to Annotated Element
Note System Architect also provides a native property that allows you to specify a comment for each symbol on a diagram, in the Graphic Comments tab.