PROPERTY_DATA

Hi everyone

Could anyone tell me please what is PROPERTY_DATA and what is it for?
There’s BACKUP_PROPERTY_DATA BackupRead()/BackupWrite() stream ID and 2
file system controls FSCTL_READ_PROPERTY_DATA and
FSCTL_WRITE_PROPERTY_DATA. But there’s no structures or anything like. Does
anybody know the case this data appears in a file?

Thanx in advance