Unmentioned, but implied, was issue of inconsistency between text and binary data. You can set text values with echo, but binary data is rather less convenient. Supporting structured data, whether it's done with an XML, C, or other syntax makes good sense. It allows a consistent snapshot to be taken and reduces the number of system calls that must be done to open, read, and close sysfs multiple one-per-attribute files. It should be mandatory that names and types of attributes mustn't change, though allowing attributes to be added, deleted or even reordered should also be supported.