YV1 is just an identifier for Volvo, each car manufacturer has one,this is because VIN number should be unique.
Some additional info:
http://www.volvoclub.org.uk/vin_80.shtml
Here the plant codes:
0 = [Sweden] Kalmar Plant
1 = [Sweden] Torslanda Plant VCT 21(Volvo Torslandaverken) (Gothenburg)
2 = [Belgium] Ghent Plant VCG 22
3 = [Canada] Halifax Plant
4 = [Italy] - Bertone models 240
5 = [Malaysia]
6 = [Australia]
7 = [Indonesia]
A = [Sweden] Uddevalla Plant (Volvo Cars/TWR (Tom Walkinshaw Racing))
B = [Italy] - Bertone Chongq 31
D = [Italy] - Bertone models 780
E = [Singapore]
F = [The Netherlands] Born Plant (NEDCAR)
J = [Sweden] Uddevalla Plant VCU 38 (Volvo Cars/ Pininfarina Sverige AB)
M = PVÖ 53
Afaik all 850 were asembled in Ghent Belgium mine including YV1LW5502S
2081xxx