A UML Comment:
- is a metaclass of UML2.1.1.
- may be owned by any element (and in MagicDraw UML this includes Packages, even though a Comment is not Packageable).
- appears in the model (repository), and thus may be found in the containment browser.
- may carry a «stereotype» (which is very useful for editorial stereotypes and for indicating quoted text).
- is a reusable Element of the model and changes made to a Comment in one diagram will propagate to other diagrams !
- can't perform callout of Element properties (other than documentation, see below).
In MagicDraw UML a «documentation» Comment is a special
case. The documentation of an Element may be displayed or even edited
in a Comment attached to an element by a handle after performing Retrieve Documentation
from the context menu for the attached Comment. Such a «documentation»
Comment DOES NOT appear directly in the model (containment browser).
Visit the following page for an examination of a MagicDraw UML XMI project file to
see how it is stored.
A UML note:
- is only notational (it is not a true UML model element)
- is not owned by an element in the model
- does not appear in the model repository (it is stored in the project file using an xmi:extension, visit the next page for an example).
- WARNING: changes made to a note in one diagram will not propagate to cloned notes in other diagrams !
- may callout Element Properties, Constraints, and Tagged Values.
Unless you are using the useful callout feature of a note, I recommend that you use a Comment ! If you don't want to display a Comment's applied stereotype(s) simply switch off the display with the Show Stereotypes options, then it will look like a plain note.
See also:

