"The two first sheets OVD BR and OVD LA show reporting on standard (fossil) fuels using traditional fuel type-based reporting.

The last two sheets named with Biofuels take the standard example as a starting point but replace consumption of MGO with biofuel blends.

On 2024-05-25 06:30, prior to departure from Hamburg,
the vessel has bunkered a blend of 28% FAME and 72% MGO (BDN number GF-ABC)
and started to use this blend in addition to using HFO.
The vessel also has some 128 tonnes of MGO onboard but it is not consumed in this example.

On 2024-05-26 11:30, shortly after filing a Noon report in Rotterdam,
the vessel has topped the previously bunkered biofuel blend with some more 21 tonnes of FAME.
The new topped blend is assigned BDN number GF-ABC-TOP. 
Consequent consumption of biofuels is from that moment of time done from BDN number GF-ABC-TOP.
HFO is still consumed in addition to the topped biofuel blend."
