Could anyone explain the difference between these two key combinations?
It seems most third-party OSX applications use
backspace to perform delete operations, but Finder instead uses
backspace. iTunes appears to use both for different operations (one moves to the trash, the other deletes from the library), while the Mail application maps them both to the same operation (delete email).
I've searched the HCI guidelines, but so far haven't found any clear definition of what these combinations are supposed to represent.