Patrick Mary - 2023-06-15

The GML export does not support the export of user defined properties; in the GML format the name of a property (called attribute) is restricted to be a 7-bit ASCII key ([a-zA-Z][a-zA-Z0-9]*) while it is a UTF-8 delimited string for Tulip.
Then only Tulip "view" properties are exported using their GML equivalent attribute.