1. A method for improving functionality of a binary representation of an XML-based content description, wherein a structure of any instance of an XML-document corresponds to a tree-like data structure including a plurality of tree nodes, the method comprising the steps of: providing that each tree node represents an element of the content description and has a structure which is defined in a schema; providing the tree nodes in the binary representation with tree branch codes; providing that the respective tree branch code has a schema branch code; extending an existing schema by utilizing unused schema branch codes in a tree node for extensions with new elements until the unused schema branch codes are all used up, and increasing a bit length of the schema branch code as necessary; and communicating a bit length change to a decoder for correctly decoding the content description in the binary representation.