What are the relevant passenger rights in case of international train travel in Europe? In my experience, railway carriers are often quite poor at informing travellers of their rights; people believe those rights depend on the flexibility of the ticket, but it does not depend on ticket type. The rights can not be signed away.
I am aware of the following two documents:
COTIF CIV, Uniform Rules concerning the Contract of International Carriage of Passengers by Rail (CIV), in any of the COTIF CIV signatories
REGULATION (EC) No 1371/2007 OF THE EUROPEAN - EUR-Lex inside the European Union (and probably some other countries like Switzerland, Norway, ...).
In addition, surely each country and each carrier has its own regulations, but do any other relevant international treaties exist within Europe?