This seems related to the issue FD-13 "As a teacher and as a developer, I would 
like the planner to have a clearly defined minimal core" on the jira backlog (it 
does not point to an issue on the issue tracker in its description).

Not sure if there are other command-line parameters affected, but there are attributes and methods that don't belong in the root class, such as the SearchSpace attribute.

(This has been on our mental agenda for a long time, so there already be an open issue for this. But I don't remember one.)

The search algorithm base class currently provides options that are not relevant for all implementations. One example we stumbled over in issue1130 (see PR https://github.com/aibasel/downward/pull/203) was the `cost_type` parameter which has no effect on iterated search but was mentioned in the documentation. Malte's comment indicates that there are more examples for parameters that should not be present in the base classe, but I didn't check myself. This issue should fix this and remove all options from the base class that are not relevant for all its derivatives.