I've noticed that in generated documents, the initial comment for an instance method is identical to the "Discussion" section for that instance method. You can see examples of this in AFNetworking's documentation, which apparently was built with appledoc 2.1.
I'm using appledoc 2.2 and see the same thing. I took a look at the templates, and apparently #hasShortDescription and #hasLongDescription are both true and #shortDescription is equal to #longDescription, which makes it impossible to switch on these without having repeats.
The Description in Apple documentation does not repeat the initial method comment. See NSArray as an example:
Did you try with --no-repeat-first-par?
Thank you sir! That was exactly it. Seems like this should be the default.