At section 4.3 UI Layer, classes and packages are indicated in italics:

However later on (and in the rest of the DG), some are given in momospaced font or in caps...
For example, in section 4.4 Command Interpreter Layer, naming is given in both caps and in monospace:

At section 4.3 UI Layer, classes and packages are indicated in italics:

However later on (and in the rest of the DG), some are given in momospaced font or in caps...
For example, in section 4.4 Command Interpreter Layer, naming is given in both caps and in monospace: