those from traffic manager and AI, so that it will later be possible to
load the data into the UFO Scenery Object Editor, to visualize and edit
parking positions, taxiing routes etc. The parser also allows to suck
arbitrary (simple) XML data files into fgfs from Nasal context.
In the long run the non-standard XML files in fgfs shall, of course, be
converted to standard format, in which no data may be stored in attributes.