Benjamin I think this is partly the documentation's fault and not yours. The documentation is not clear at all in many places and I've raised my voice elsewhere. It should follow some sort of consistent documentation format whereas it does not.
Many places the examples use a particular 'field' but that field is not explained anywhere. For example "total" in <tasks total=""> is not explained anywhere. API 1.0's documentation was more clear what it did which has now changed in 2.0 and the same rules don't apply anymore.