Hi, Here's a use case that I can't seem to find a way to do using boost.serialization. Say with version 1, I want to serialize X Y and Z. These are hierarchical and expensive data structures. Now, with version 2, I do not need to create Y objects anymore. Yet, I still have to open version 1 files for backward compatibility. So, when loading version 1 files, I want to skip reading Y objects. How do I do that without having to create a temporary Y object that will be discarded later? (I'm particularly interested with XML archives. If I had control over the xml parser, that would simply mean ignoring everything from the current tag until the next matching tag is found). Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net