Does anyone the YUASA number for a 2012.
Service manual says GYZ20L
Yuasa guide says GYZ20L or YTX20L
YTX20L-BS is a YTX20L with the acid supplied separate (Bottle Supplied) for initialization at the time the battery is put into service.
Any of the 3 will work.
GYZ series are only available factory activated.
Yes, it's the same battery as the '18-'19.
Earlier 1832's used the older design YTX20L. Physical size and terminals are the same, so either can be used.
GYZ has slightly higher AH (Amp-Hour) capacity and slightly less CCA (cold cranking amps)
Honda seems to the the AH increase is more beneficial for GoldWing use.
Application Guide and Technical Manual are both available in pdf here:
https://www.yuasabatteries.com/