The "creator" attribute is required and "extensions" is the correct
name of this element.
Validated with SAXCount from the xerces-c package:
$ SAXCount -v=always -n -s -f notes.gpx
Original error messages:
Error at file /home/markus/notes.gpx, line 2, char 171
Message: no declaration found for element 'gpx'
Error at file /home/markus/notes.gpx, line 2, char 171
Message: attribute 'version' is not declared for element 'gpx'
After adding the "xmlns" attribute:
Error at file /home/markus/notes.gpx, line 2, char 213
Message: missing required attribute 'creator'
Error at file /home/markus/notes.gpx, line 18, char 14
Message: no declaration found for element 'extension'
Error at file /home/markus/notes.gpx, line 26, char 7
Message: element 'extension' is not allowed for content model '(ele?,time?,magvar?,geoidheight?,name?,cmt?,desc?,src?,link*,sym?,type?,fix?,sat?,hdop?,vdop?,pdop?,ageofdgpsdata?,dgpsid?,extensions?)'
The current errors now are caused by the missing XML schema for the
extensions.
Also add the time, name and link elements.
