Over the past week the "XSG" beacon has appeared with a new format, with the prefix "de" added to the callsign. As per usual the transmission is preceded with the four buzz tones. The only other beacon to use "de" is the Hellenic Met Office beacon "SVO" in Greece but has no preceding buzz tones.
02nd Nov 2019 0920z 8.431MHz CW "de XSG" Shanghai Marine Radio, China 569 report.
30th Oct 2019 1059z 8.435MHz CW "de XSG" Shanghai Marine Radio, China 539 report.
All of the other Chinese marine radio beacons XSV, XSQ etc and TAH in Turkey still operate as per normal without the "de" prefix added to the call format.