I have an assignment that states the following criteria:
For this view you may use a truncated version of
your Design Class Diagram (DCD) including
only the architecturally significant classes.
For context, this is for the Logical View of a 4 + 1 Architectural View. How does a design class diagram (DCD) differ from a regular class diagram? Is it the UML diagram without the functions or variables included (i.e. just the names of the classes and their interactions with each other)?
Most of the time, people model their code. That's good! In that case, class diagram modeling is used to graphically represent the structure of (object-oriented) classes: class, method, attribute, annotations with stereotypes. Imagine all the JPA, Spring, whatever annotations in the class diagram of a JPA-J2EE based architecture...
As it's said above, the "design class diagram" should only design your domain model, from an architecture level. What are the basic entities your structural system rely on? No details about the programming language, no "dto", "dao" or technical stuff like that. Here's a good example I use: online shopping cart domain model. It only contains the architecturally significant classes.
HTH, Tom