Redundancy between signal and its sub-elements
As per version 2.5 of railML 2.x there is a redundancy between the signal and its attributes and the attributes of its subelements. one such redundancy is the mandatory attribute @switchable of signal, which was reintroduced with version 2.5 after being deprecated in 2.2. However there also is an attribute @switchable at the following subelements: speed, etcs, levelCrossing, trainRadio, catenary, line, milepost and braking. None of these have become deprecated. As such it is unclear how to interpret a railML 2.5 signal. We should provide documentation for that and at least explain how it is meant. For the maintenance release of 2.5 that is planned we should include a change that declares the ones that are not necessary anylonger as deprecated (probably the ones on the lower level).