UML 2 Note Style Guidelines

A UML note is a modeling construct for adding textual information - such as a comment, constraint definition, or method body - to UML diagrams. Notes are depicted as a rectangle with the top-right corner folded over.

Figure 1. A summary note for a diagram.

Figure 2. Indicating uncertainty on a diagram.


  1. Describe Diagrams With a Note. In Figure 1 you see that the name of the system, the purpose of the diagram, and its owner is indicated.
  2. Set a Convention for Placement of Diagram Descriptions.
  3. Left-Justify Text in Notes. It is common practice to left-justify text in UML notes, as you see in Figure 1 and Figure 2.
  4. Prefer Notes Over OCL to Indicate Constraints. Figure 2 includes a very simple example of OCL, {ordered, FIFO}, code that programmers may understand but few project stakeholder are likely to.
  5. Follow Common Coding Conventions for OCL and ASL. The book The Elements of Java Style describes Java coding guidance which you can modify for OCL and ASL.