lyrics position "above" is lost after export to musicxml and re-import

When exporting a file that uses the setting "above" for lyrics, this attribute seems not to be written to the musicxml file during export.
When re-importing such a file, all lyrics are "below".
musicxml defines an attribute "placement" that can be set to above or below. It seems that this would be the proper place for export (and import).

This is also interesting for interchange with other Software. And with the music scanner Audiveris, that uses musicxml-output.