The DASH spec also talks about a specific range format on the BaseURL tag with the $start$ and $end$ variables, but according to a thread on the DASH-IF feedback issue tracker, this is considered deprecated.

Also not sure why the byterange (previously range) attribute of each Segment is stored as (start,length) instead of (start,end). The length format comes from the HLS spec (length@offset), but DASH keeps the same format as the HTTP Range header, namely start-end, so the conversion that is done by the parser and fetch() method later on is actually totally unnecessary. It could be changed later, but not really important now.