PROBLEM:
When I run doxygen on Objective-C source code with the following code block,
no documentation is generated for that method -- no signature, parameters or
doc comment.

CAUSE:
I tracked the cause down to this:
A comment line that starts with the string "// Author" prevents the entire
documentation for that method from being generated

SOLUTION:
Add a word before "Author", such as "// The authorization has finished"
enables the method's documentation to be generated

-------------------------------------------------------------
// A protocol implemented by the client.
@protocol MyClassDelegate

// Authorization is finished
- (void)finishedWithAuth:(OAuth2Authentication *)auth;

@end
--------------------------------------------------------------

$ doxygen --version
1.8.3.1